Systems Engineering
What is the selection criteria for CI?
- Major system subsystems and components. - Common components or subsystems. - Components containing software and firmware. - Components satisfying logical groups of specified system requirements. - External Interfaces. - Mission critical, safety-related, or developmental items. - Likely rate of change. - Design and Development organisational responsibility. - Maintenance concepts.
What are the COTS disadvantages?
- May not be perfectly suitable. - Technology base likely to be old. - Technology could be immature. - Use and support constrained by warranty or IP. - Support; back to the supplier. - Little documentation available. - Additional (undesirable) functionality - May not be validated in the environment.
What are the Developmental items advantages?
- May precisely meet our requirements in terms of form, fit and function. - All aspects will be understood (and controlled) from a security perspective.
What are the Cost Estimating methods?
- Analogous. - Parametric (stochastic). - Bottom-up/engineering (deterministic).
What is Acceptance Test and Evaluation (AT&E)?
- Formal acceptance testing on behalf of customer. - Between the Acquisition and Utilisation Phases.
What are the progressive established baselines that help manage Configuration?
- Functional Baseline (FBL). - Allocated Baseline (ABL). - Product Baseline (PBL).
What are the 3 types of Configuration Audits?
- Functional Configuration Audit (FCA). - Physical Configuration Audit (PCA). - Configuration Management System Audit.
What are the main reasons for modifications?
- Rectification of system performance problems. - Failures identified by the FRACAS process. - New or revised operational requirements. - Ensure continued supportability.
What are the risk treatment options?
- Risk Avoidance. - Risk Mitigation. - Risk Transfer. - Risk Acceptance.
What documentation does the TRR review?
- Test and Evaluation Master Plan (TEMP). - Test plans. - Formal and informal test results. - Supporting documentation. - Support, test equipment, and facilities.
What are the key tenets of systems engineering?
- Top-down approach. - Requirements engineering. - Life-cycle focus. - System optimization and balance. - Integration of specialisations and disciplines. - Management.
What are the SE tools covered in SE class?
- Verification. - Failure Analysis. - Technical Metrics. - Human Factors. - Use Cases. - ReqView. - LSA. - Innoslate.
Why is defining interfaces a critical part of Preliminary Design?
- determine successful operation of the system once integrated. - place additional limitations and requirements on the design of the individual subsystems/CIs.
What is the definition of a project?
A temporary endeavour undertaken to create a unique product, service or result.
In Earned Value Management, what are assigned to each Work Package?
AC, PV and EV.
From the point of initiation, why should you as a Project Manager ensure assumptions are documented?
Assumptions might prove to be incorrect, analysis of assumptions is key to risk identification.
Following SDR, we move into Preliminary Design. One of the early activities in Preliminary is to identify and specify the subsystems in the design. What happens during Preliminary Design?
During early preliminary design, the contractor continues refining their understanding of the subsystems. They continue the requirements analysis process using the SyRS as their basis, and derive and allocate requirements from the SyRS to each of the subsystems. Interface requirements are an important part of this process.
What is Lag?
Lag is the amount of time a successor activity will be delayed with respect to a predecessor activity. e.g. Start to Start + 10 (SS+10)
What is the formula for Reliability?
R(t)= e^(−λt) = e^(−t/MTBF) Where: R(t): Reliability (fraction of 1. 1 is 100% certain) MTBF: Mean to between failure (hrs) λ: Failure Rate (failures per hr)
What are the estimation methods?
ROM, Definitive estimate.
What is the Specific artefact produced as a result of the verification process?
Verification Matrix.
What is a PCA?
The objective of the Physical Configuration Audit (PCA) is to provide confidence that the as-built CIs match the low-level specifications such as the Product Specifications, assembly specifications, drawings and technical data.
What is the project budget?
The project budget is the amount allocated to the project to achieve its objectives (the funding requirement). - The budget must cover the aggregated cost estimates but includes reserves: - Management reserve. - Contingency reserves.
What are the 2 broad ways that a system can be described as?
- Logical (or functional)—what system will do, how well, how tested, under what conditions to perform. - Physical—what system elements, look, how are to be manufactured, integrated, tested.
What is Bottom-up (or Engineering) Estimating?
- Estimates are done for each work package (lowest level of the WBS). - The estimate and the basis-of-estimate are recorded in the WBS dictionary. - This is the only way to achieve a definitive estimate for the performance management baseline.
What is the Critical Path Method?
- Estimates project duration and the flexibility of the schedule. - Calculates the early start, early finish, late start and late finish for each work package (by forward pass and backward pass analysis). - The critical path is the longest sequence of work packages. - Work packages on the critical path have no float. - Manual calculation uses the activity-on-node diagram.
What is Operational Test and Evaluation (OT&E)?
- Focuses on functional or operational testing of the system. - Generally undertaken by users following acceptance. - Some OT&E can occur earlier during Acquisition Phase, particularly for large, phased projects.
What does the PMBOK provide?
- Generally recognised good practice. - Applicable to most projects, most of the time. - Provides a shared vocabulary. - Not a methodology (compare to PRINCE2). - Widely used - referred to by most texts and methodologies.
What are the functions of Configuration Management?
- Identification (of the items to be placed under control). - Control (of these items through effective change management processes). - Status accounting (accurate and up to date configuration information on each CI). - Audits (confirmation of correct operation of the configuration management process).
What are the 5 project management process groups?
- Initiate - Plan - Execute - Monitor & Control - Closing
What is the Contingency reserves?
- Inside the cost baseline (project managers responsibility). - For "known unknowns" - for treating identified risks. - Unallocated (withheld by PM) and allocated (assigned to a work package).
What are the MOTS disadvantages?
- Maintenance and support agreements may be voided if the item is altered. - The effort required to modify items is usually grossly underestimated in terms of both cost and time.
Within the Utilization Phase; for Operational Use and System Support, what are the major system activities?
- Operational Use - System Support - Operational Test and Evaluation - Modifications
What are human characteristics relevant to the system?
- Physical; size, strength. - Psychological; the working of the mind and its impact on behaviours. - Cultural.
What are the 4 very broad phases of a system life cycle?
- Pre-acquisition Phase. - Acquisition Phase. - Utilization Phase. - Retirement Phase.
Risk is a function of?
- Probability of the risk occurring (likelihood) - Impact on the project should the risk occur (consequences).
What is Production and Construction?
- Production refers to manufacturing and procurement effort needed to support construction. - Construction is the assembly and building of the system.
What are the 5 phases of LSA?
- Program planning and control. - Mission and Support Systems Definition. - Preparation and Evaluation of Alternatives. - Determination of Logistic Support Resource Requirements. - Supportability and Control.
How can the overall failure rate of safety critical systems be improved?
- Redundancy. (multiple subsystems, same task). - Design diversity. (different manufacturers) - Dissimilar design. (generators vs batteries) - Fault-tolerant and fail-safe designs. (traffic lights flash orange) - Integrated protection. (circuit breakers to protect sensitive equipment)
What are the considerations for system, subsystem & component requirements and constraints that are imposed by system safety?
- Required failure rates (as discussed with DFCS example). - Fault detection and annunciation requirements (detecting and alerting people to failure). - Fault recovery requirements (being able to reset/reboot a system to bring it back online). - Spare capacity requirements (allowing future upgrades without hardware changes).
What are the 7 classes of entities for Innoslate?
- Requirement. - Artefact. - Action. - Asset. - Input/Output. - Conduit. - Characteristic.
What are the accuracy levels for cost estimates?
- Rough Order of Magnitude (ROM). -25% to +75% - Preliminary. -10% to +30% - Definitive estimate. -5% to +10%
What are the 10 project management knowledge areas?
- Scope. - Time. - Cost. - Quality. - Integration. - Risk. - Human Resource. - Procurement. - Communications. - Stakeholder.
What is Fast tracking?
- Start a work package before the previous on has finished. - May increase risks and create rework.
What do Change Proposals contain?
- Statement outlining the change. - Reasons for the change. - Alternatives available. - Preferred alternative detail. - Impact of the change especially interface impacts. - Draft design documentation reflecting the change.
ReqView is a comprehensive requirements management system tool. According to Systems Engineering Practice Text, what are the core features essential for requirements management.
- Support Change control. - Does not enforce a particular requirements engineering process. - Allows specific requirements to be retrieved. - Supports forward and backward traceability.
Interface information is contained in what documentation?
- SyRS. - Interface Control Documents (ICDs). - Development Specifications. - Product Specifications.
Why do we need Configuration Management?
- To establish the technical integrity of our systems as we engineer them. - To maintain the integrity of our systems as they pass through production and into the support phase of their lifecycle. - This is needed to support product development, maintenance, modification, and disposal.
What activities are included in the Retirement Phase?
- Transportation. - Handling. - Decomposition. - Processing.
What are the techniques used by Agile?
- User stories. - Backlog. - Sprints. - Users embedded in the team. - Decisions led by the team. - Quality led by the team.
What is the difference between Verification & Validation?
- Verification is the evaluation of whether or not a product, service, system or component complies with a regulation, requirement or condition. - Validation is the assurance that a product, service, system meets the needs of a customer or stakeholders. - Verification relates more to one element whereas - validation relates more to a set of elements considering them as a whole.
What is the general approach of Agile?
- Welcome changing requirements, even late in development. - Give continuous attention to technical excellence and good design. - Use face-to-face conversations as the primary communication means. - Simplify processes and remove unproductive activities.
What does Conceptual Design address?
- articulate the needs. - analyse and document the system-level requirements flowing from the needs. - complete a logical design of the system. - major product is the Initial Functional Baseline (FBL).
What are project constraints?
- budget and schedule constraints. - the resource allocations to the project. - externally imposed deliverables and acquisition timeframes.
What are the 6 steps of a FRACAS based on MIL-STD-2155(AS)?
- failure reporting. - failure analysis. - failure verification. - corrective action. - failure report and close-out. - identification and control of failed items.
What are the 3 retirement tasks to consider during system design?
- identify the reasons for potential retirement. - identify potential retirement methods for the system. - identify design issues that may arise from the consideration of each retirement method.
What are the COTS advantages?
- readily available. - much cheaper than Developmental approach. - maintenance and support; established. - reduced technical risk. - may be validated in the environment.
What does a system comprise of?
- system elements. - interconnections (interactions) between elements. - an external system boundary.
What can cause the system to go into Retirement phase?
- the business has no further need for the system. - it no longer can meet the functions required of it by the organisation. - it is no longer cost-effective to keep it in service.
What is the accuracy of the ROM cost estimation method?
-25% to +75%
What is the basic systems engineering process loop that is applied iteratively throughout the system life cycle?
-analysis. -synthesis. -evaluation.
What can be done if there is a conflict between design and requirements?
- Investigate other areas of design for spare space - Use traceability to understand the relationship between the design and the functional architecture. - Understand the stakeholder requirements at risk. - Alert the stakeholders and see whether we have any room to move. - Check for a priority among the conflicting requirements (in a worse case, we may have to meet the highest priority requirements at the expense of others).
What is Analysis?
- Involves collating and processing test data obtained (usually from test). - May involve interpolation and extrapolation of data etc. - Could be by mathematical model or simulation. - Could be via similarity analysis.
What is a Demonstration?
- Involves observation of some aspect of the system's function and/or performance. - Generally does not require specialised equipment.
What is a Test?
- Involves the operation of the system using test equipment to collect data. - Uses a test specification or procedure.
How is the retirement phase affected by human factors considerations?
- It ensures that the personnel carrying out the retirement or disposal is operating in a safe environment. - It ensures that the disposal or the retirement of the system does not create or release harmful substance that might affect the operator's health. - It ensures sufficient safety equipment for the operator as required for the task.
What is the Management reserve?
- Kept outside the cost baseline (sponsors responsibility). - For "unknown unknowns" - unforeseen changes within the project scope. - A formal change to the cost baseline is conducted as the reserve is consumed.
What are the benefits of correctly applied systems engineering?
- LCC savings. - Reduction in overall acquisition schedule. - Reduction in technical risk. - Quality system.
What is Developmental Test and Evaluation (DT&E)?
- Largely undertaken in the Acquisition Phase. - Support design and development effort. - Generally undertaken by contractors.
What is the definition of Configuration Mangement?
The act of controlling and managing the physical and functional make-up of the configuration items that comprise the system.
What is the aim of the CDR?
The aims of the Critical Design Review (CDR) include: - Evaluation of the design. - Determination of readiness for production/construction. - Determination of maturity of software. - Determination of design compatibility. - Establishment of the PBL (Product Base Line).
What is the Critical Path?
The sequence of activities that represents the longest path through a project, which determines the shortest possible project duration.
What is the definition for Critical Path?
The sequence of activities that represents the longest path through a project, which determines the shortest possible project duration.
To use the Design Space appropriately, who must be consulted?
The stakeholders.
What happens during the Utilisation phase?
The system is operated and supported. The system may undergo a number of modifications and upgrades.
What is the next processing step, once a system-in-use-story is obtained?
The system-in-use-story is then translated into structured language.
Where is the technical metrics program planned and documented?
The technical metrics program would be planned via the SEMP and documented in the relevant section of the contract Statement of Work (SOW).
How is the technical metrics and verification regimes related?
The technical metrics regime and the Verification regime need to be integrated. Verification provides the data for analysing the progress of technical metrics.
By considering a system as a capability, rather than a piece of hardware or software, what can system engineering ensure?
The technical requirements of the 'equipment' can be developed with an appreciation of personnel, support, training and other critical inputs to capability.
Matrix Organisation is a type of organisational structure, what is a Matrix Organisation?
A matrix allocating organisational resources, between organisational sections to organisation projects.
Why start with the requirements rather than the physical solution.
Better chance of success. May not consider all possible solutions. There maybe a reason why a particular solution is not appropriate.
What is the Acquisition phase focused on? During the Acquisition phase, what is the system defined in terms of?
Bringing the system into being and into service in the organisation. The system is defined in terms of: - business requirements. - stakeholder requirements. - system requirements.
What is a FCA?
Functional Configuration Audit (FCA) is used to verify and certify that the performance of the CI meets the specified requirements. The functionality demonstrated by test and evaluation for that CI is the same in its Development Specifications and Product Specifications.
What is FHA?
Functional Hazard Analysis (FHA) aims to understand the relationship between system functions, functional failures/malfunctions and safety hazards (leads to the identification of safety-significant functions (SSF).
What are human factors in SE?
Human factors in SE is the design of machines, machine systems, work methods, and environments to take into account the safety, comfort, and productiveness of human users and operators.
At what stage in the SE process are human factors used as a tool?
Human factors is a tool that should be considered for all phases of the SE process to ensure that the product will meet the requirements of the end-user and stakeholders.
How early in the SE lifecycle should human factors be considered?
Human factors must be considered as early as possible in the SE lifecycle. It will even be a key factor in pre-acquisition phase of some systems. For example, human mobility will be a central tenet in justifying the business need for a new individual load-carrying system for combat soldiers.
What are the 3 broad alternatives open to designers?
Commercial Off-The-Shelf; COTS. Modified COTS. Developmental approach.
What is the aim of CCA?
Common Cause Analysis (CCA) identifies possible common causes of failure in our systems. Single events that impact on multiple parts of the system. In parallel with the FHA and SSA. - Cause redundant systems to all fail. - Covers zonal issues. - Mitigating human-induced causes of failure.
What are the life cycle activities that comprise the Acquisition Phase?
Conceptual Design. Preliminary Design. Detailed Design and Development. Construction and/or Production.
What is the definition of CI?
Configuration Item (CI) can be defined as an aggregation of hardware and software that satisfies an end-use function, whose requirements are specified and designated for separate configuration management.
Technical metrics help to?
Confirm that key parameters are meeting their specified requirements. (NEED TO CHECK ANSWER WITH GROUP 3)
What document is submitted to the Change Control Board (CCB) to trigger a Engineering Change?
Engineering Change Request (ECR).
What is an Engineering change?
Engineering changes are required where the departure from the specification is going to result in either a change in design or a change in requirement.
Why must human factors be considered SE?
Human factors treats the human in a system as an interfacing component of that system, with its own unique inputs, outputs and constraints such as stress and fatigue. This allows for the human-system interface to be more robust and reliable, increasing the chances of the overall success of the system.
What does a mission do for a system?
Provides a solution to a business problem. Its the basis for the ultimate test of the system's fitness-for-purpose.
What are the PMBOK Knowledge Areas?
Scope. Time. Cost. Quality. Integration. Risk. Human resource. Procurement. Communications. Stakeholder.
The Standish Group issued a Chaos report on project success and failure in the mid 1990s that was based on many projects across different industries and sectors. What did its conclusions include?
That fundamental systems engineering themes such as stakeholder engagement and requirements management are critical to the success of projects.
What does the Pre-acquisition Phase ensure?
That only feasible, cost-effective projects are taken forward to acquisition.
Who is normally responsible for the Preliminary Design?
The Contractor.
Who is normally responsible for the FBL?
The Customer.
What is a FQR?
The Formal Qualification Review (FQR) may be required to verify that the performance of each of the CIs meets all the functional requirements when integrated together into the system.
What is the aim of the PDR?
The Preliminary Design Review aims to ensure the adequacy of the preliminary design effort prior to releasing the allocated baseline and allowing detailed design to commence.
What does the PBL detail?
The Product Base Line (PBL) is a detailed description of the 'products' that will meet the requirements allocated to them in the ABL.
Stakeholder Needs and Requirements (SNR) are developed during Conceptual Design. What does the SNR contain?
The SNR contains both the agreed lifecycle concepts and the agreed stakeholder requirements and constraints associated with the new system.
What is the process for developing a use case?
The use case is predominately used within the acquisition and preliminary design phase of the systems engineering lifecycle and does so to allow an easy way to understand the required business needs and requirements, stakeholders needs and requirements as well as the systems requirements.
In use cases, what are actors?
The use case process often starts by identifying all the actors and listing all their business goals. Actors are people or interfacing systems that have a behaviour and a business goal.
What is the aim of technical metrics and how is this achieved?
The whole point of the technical metrics program is to address technical metrics issues urgently and as early as possible. Trends need to be analysed not only the out-of-bounds conditions on the tolerance bands. Trends are detected by sampling the technical metrics sufficiently often - be careful interpolating.
What is challenge associated with software verification that hardware verification may not possess?
There are particular challenges and approaches such as hardware verification compared to software verification. For example, software verification is notoriously difficult and is associated with special techniques. Statistical techniques are sometimes used to optimise the coverage of test cases.
What is the purpose of Configuration Audits?
To confirm the correct operation of the CM system.
Regardless of the failure analysis method used, what is always important?
To document the findings and to trace derived requirements into the requirements engineering process.
What is the aim of System Safety Analysis (Preliminary SSA (PSSA) and SSA)?
To understand how the proposed system-level (and lower level) design will meet specified and derived safety-related requirements.
Why do Designers and Customers look horizontally along an Allocation Matrix?
To understand the impact each requirement is having on the design. The horizontal direction becomes particularly critical when changes to requirements are proposed. Quickly assess the likely impact of a changed requirement on the design. Later the change, bigger the impact.
Why do Designers look vertically down an Allocation Matrix?
To understand the requirements allocated to their CIs.
In regards to human factors, how can prototyping help design?
Tools like prototyping are commonly used from the earliest stages in the lifecycle to help ensure that human factors are correctly accommodated in the requirements and subsequent design.
Who should carry out verification?
Verification is a specialist field. It is often desirable to have independent verification teams for the expertise required but also because the developer invariably has a vested interest in achieving good results.
Verification is usually considered whilst drafting and specifying requirements. Why is it important to think about verification at the same time as the requirements are written?
Verification is an integral part of an effective requirement statement and the requirement statement may be considered incomplete without it.
How is the system and subsystem levels of Verification structured?
Verification ultimately verifies system compliance with the SyRS, but this is done via the specification hierarchy and requirements traceability. For example, the subsystem specs (dev specs) are verified by subsystem verification, the component specs (product specs) are verified by component/product/unit verification. Note again the idea of progressive elaboration of system designs, and the design of verification.
In terms of time, resources, requirements and features/functions, how does Agile differ from Waterfall?
Waterfall - Given fixed requirements, the plan drives resource and time estimates. Agile - Given fixed time and resources, business value drives features/functions to be included.
What is the tool called that decomposes the global scope into small manageable chucks?
Work Breakdown Structure.
What is the difference between WBS & RBS?
Work Breakdown Structure; WBS is physical and Requirements Breakdown Structure; RBS is functional.
What level should the Work package be aimed at?
Work package level should be at the highest level possible to achieve a,b,c. Not any lower. Decompose scope into work package, to: a. Represent a deliverable. b. Cost and schedule activity. c. Allows to assign to individual.
What is the lowest level of detail for a Work Breakdown Structure (WBS)?
Work package. - Can be assigned to a single perform group. - Can be definitively estimated (+/- 10%). - Associated with a deliverable that can be objectively verified and accepted. - Scale; duration about ½ reporting period to 2 reporting periods.
What is the formula for Failure Rate?
λ = 1/MTBF Where: MTBF Mean to between failure (hrs) λ Failure Rate (failures per hr)
When does Technical Integrity exist?
- All system elements are well defined and documented. - Traceability is established and maintained to explain how system functions are provided by the design.
Human factors is a catch-all term that covers a wide range of overlapping and related disciplines these include?
- Ergonomics. - Anthropometrics. - Psychology.
What are the Developmental items disadvantages?
- Advantage may not eventuate. - Significant effort associated with developing items. - Maintenance and support needs to be developed and deployed.
What is Crashing?
- Add resources to critical work packages to shorten the work package duration. - Often increases project costs (note the "mythical man month"). - Often increases risks.
What are the typical methods for verification of requirements?
- Analysis. - Demonstration. - Inspection. - Test.
What supporting detail should be included for activity cost estimates?
- Basis of estimate. - Assumptions. - Constraints. - Range of possible estimates. - Confidence level of final estimate.
Human factors is a life-cycle concept in that all humans interfacing with the system throughout its lifecycle should be considered, these include?
- Builders/manufacturers. - Operators. - Maintainers. - Disposers.
What are the products produced from Conceptual Design?
- Business Needs and Requirements (BNR). - Stakeholder Needs and Requirements (SNR). - System Requirement Specification (SyRS). - Initial Functional Baseline (FBL).
What makes a requirement a Technical Performance Measures (TPM)?
- Central to the system meeting stakeholder expectations. - Particularly risky for some reason. - Typical lead indicators of system development progress.
How are severity or impact of Changes classified?
- Class 1 changes are major changes and involve form, fit or function and will therefore impact all the way up to and including the FBL. Customers involved. - Class 2 changes are minor changes not impacting on FBL. Customers only informed.
What are the 8 System Requirements quality factors checked by the Innoslate quality check tool?
- Clear and Complete. - Consistent and Correct. - Designable and Feasible. - Traceable and Verifiable.
How do Customers and Contractors use systems engineering?
- Customers use systems engineering to define system requirements, monitor contractor progress and risk. - Contractors use systems engineering to develop effective processes for the design, development and test of systems.
What are the major activities of Detailed Design & Development?
- Describing the lower-level assemblies and components. - Defining the characteristics of those items through specifications and design data. - Finalising the design of all interfaces necessary to support system integration. - Procuring items COTS or designing them. - Developing prototypes or engineering models of the CIs. - Conducting a Critical Design Review (CDR) to confirm that design is ready for construction and production.
Who decides on the technical metrics that are to be used throughout a SE project?
A collaborative collection of: Systems Engineer. Stakeholders. Contractor. Customer. (NEED TO CHECK ANSWER WITH GROUP 3)
What is a Safety Case?
A collection of metrics during integration and production to be able to mount a body of objective evidence that the system is indeed safe to operate. Used to support certification of the system if required.
What is the definition of a system?
A combination of interacting elements organised to achieve one or more stated purposes.
What is the definition of a system? (ISO/IEC 15288)
A combination of interacting elements organised to achieve one or more stated purposes.
What is the definition of a specification? (EIA-632)
A document that contains specified requirements for a product and the means to be used to determine that the product satisfies these requirements.
What is a Development Specification?
A document that details the collection of system, subsystem and derived requirements for each Configuration Item (CI), describing the requirements for that CI.
What is FRACAS?
A failure reporting, analysis, and corrective action system (FRACAS) is a closed-loop system designed to continually maintain visibility into system operation and support.
What is Analogous Estimating?
A project which is comparable to another project in significant respects. Uses historical data from a similar activity or project. - Similarity is judged by chosen parameters such as type, size, complexity or physical characteristic. - Expert judgement is needed to make the comparison and adjust accordingly.
What is the PMBOK?
A recognised PM practice, not necessarily the latest and greatest, because of how broad Project Management is. Not linked to systems development, because there is Projects that don't have SE and vice-versa.
What is Verification?
A set of actions used to check the correctness of any element. - Confirmation that specified requirements have been fulfilled. - Uses objective evidence. - Compares a system or system element against required characteristics. - Used to identify faults/defects.
What is a methodology?
A specified framework used to structure, plan, and control the process of developing a system. Model or approach is more general and may underpin a methodology.
How is a Project defined?
A temporary endeavour undertaken to develop a unique product or service.
what is a use case?
A use case is a systems engineering tool that can be used to assist in the defining of the behaviour of a system prior to the detailed system requirements phase of the systems engineering lifecycle.
What is Resource Levelling and Smoothing?
Aims to keep the allocation of each resource type below a given constraint or used in the most efficient way. - Resource availability constraints. - Start-up and wind-down costs. - Use efficiently.
What should be planned for in the verification process?
All the required tools, test data, configuration data, constraints, costs scheduling, interfaces and methods used.
Following production and construction, the system enters the utilisation phase. Critical supportability issue should have influenced the design of the system throughout the systems engineering process. What systems engineering occurs in the utilisation phase?
Although systems engineering involvement is now minimal, systems engineering processes can be used to define, design and implement modification programs involving the system throughout its operational life.
What does Status Accounting provide?
An accurate snap shot about the CIs and their associated documentation set.
What is Earned Value Management?
An approach that readily shows deviations in project performance by combining cost, schedule and resource measures. Uses three key dimensions for each work package: - Planned value. - Actual cost. - Earned value.
What can assist with interpolation/extrapolation of Technical metrics data and what can the information be used for?
An appropriate sampling rate can assist with interpolation/extrapolation of performance and the prediction of trends in the data. This is what gives us a lot of information about whether we are in trouble or not with the Technical metrics.
How does an effective Project Management organisation deal with projects?
An effective Project Management organisation has to employ consistent and repeatable processes and practices across all projects.
What is systems engineering?
An interdisciplinary collaborative approach to derive, evolve, and verify a life-cycle balanced system solution which satisfies customer expectations and meets public acceptability.
How is the human operator interpreted to benefit the system?
Analysis of the human operator is required to synthesis specific system requirements in the acquisition phase.
How is the systems engineering process built around the fundamental 'analysis-synthesis-evaluation' loop?
Analysis-synthesis-evaluation is applied iteratively and continually throughout the lifecycle by both the customer, during the early stages, and the contractor, during the latter stages.
What is Safety Engineering?
Applied risk management discipline - uses the concepts already covered to provide a level of assurance that our engineered systems are as safe as reasonably practical. - Closely related to and integrated with the systems engineering discipline via two-way flow of information.
When developing use cases, how can you ensure that all goals are covered?
As the full set of use cases is developed, the goals can be "ticked off" to ensure each goal is covered by at least one use case.
What does a Rationale provide for a requirement?
Background information about why a requirement (or group of requirements) exist in the current form.
What does CM aim to mitigate?
CM - a lifecycle discipline that mitigates risks associated with loosing configuration control & technical integrity of our systems.
We looked at three broad design options when it came to subsystem-level synthesis; development approaches, commercial off the shelf (COTS) approaches, and modified COTS approaches. What are the pros and cons of the different options?
COTS will be available with known lead times, known costs and demonstrated function and performance. They also generally have logistics support arrangements in place. Technical data associated with COTS may not be at the required level to support integration, they may not have been qualified in all environments, such as military environments, and they may represent obsolescence risks.
What is the name of the funds allocated to known unknowns, held by the Project Manager?
Contingency Reserve.
What is the name of the process for shorting schedule duration for least incremental cost by adding resources?
Crashing.
How is the critical path chosen using the Critical Path Method?
Critical Path has zero Total Float. Pick the path that has 0 in the middle bottom box of all path activities.
We move into a Detailed Design and Development stage whenever there are elements of our design that are not off the shelf, or where we need to make some modifications to off the shelf items. What is the Detailed Design process and its output?
Detailed design and development is an iterative process that involves design, prototyping, testing, reviews and redesign until we are satisfied with the design. It also includes maintaining a good record of the parts, materials and fabrication processes that are needed to produce our design.
What does a WBS Dictionary provide?
Detailed information about each element of the WBS regarding scope, deliverables, scheduling, resources, costs.
What is a Project Charter?
Formally authorises the project and gives Project Manager the authority to commit resources.
How do technical metrics differ from project management performance measures?
Don't confuse technical metrics with Project Management performance measures covering project cost and schedule. Technical metrics give an additional predictive measure of progress and risks. The UCWES project might be on time and within budget but might never meet its flight endurance target. Technical metrics provide early warning of such a situation.
What is regression verification?
Each change of specification or product can invalidate verification that has already been completed. In this case, regression verification is undertaken to reassure earlier products.
In regards to use cases, what does system-in-use-story describe?
Each use case should have system-in-use-story that describes the operational usage of the system in "user speak". These are sometimes called vignettes or mission profiles. The system-in-use-story helps relate the non-technical, end user to the functional scope of the system.
What is the definition of risk? (ISO 31000:2009)
Effect of uncertainty on objectives.
What are the most common forms of system failure analysis?
FMEA/FMECA, fault tree analysis, root cause analysis and hazard analysis are the most common forms of system failure analysis. These techniques are often used in conjunction to predict what could go wrong with a system and to incorporate this information into the development and production of a system.
What is the difference between FMECA and FMEA?
FMECA is similar to FMEA but includes consideration of the criticality of a failure.
What part of the lifecycle could failures occur and what are they caused by?
Failure analysis is a lifecycle concept in that the causes of failure in each lifecycle phase must be considered. For example, failures could be caused by shortcomings in the design process, shortcomings in the manufacturing process or shortcomings in the maintenance process.
When and at what level is Failure analysis done?
Failure analysis is done progressively throughout the development of a system. In the early stages, it is done at a high-level and will influence system requirements and architectures, in the later stages it is done at a very low level and will influence the detailed design of components and assemblies.
What are Critical and Safety Critical functions?
Failure analysis relates to the assurance of all required functions. "Critical" failures are those that prevent the achievement of a system's mission. "Safety critical" failures are when a human operator is injured or killed. Note: failure analysis is not only safety analysis.
What is Parametric (or Stochastic) Estimating?
Having a pattern that may be analysed statistically but may not be predicted precisely. - Uses an algorithm to calculate cost or duration based on historical data and project parameters. - Often based on historical productivity.
What is the most important information captured by Business Requirements Specification (BRS)?
High-level constraints, system mission/goals/objectives, preliminary operational scenarios and validation criteria, often in the form of Critical Issues and Critical Operational Issues.
What does the Project Management Plan define?
How the project will executed, monitored, controlled and closed. A living document that "holds" the current status of all PM processes.
Which of these bests describes the process for developing a use case?
Identify the actors, initial brainstorming, identify the relevant triggers, draft a sequence of events, draft a normal flow of events, draft a sub flow of events and exception flow of events. Finalise the use case.
What is a variance?
If the failure to meet the minimum requirements is temporary in nature, limited to only a small percentage of the supplies or a very minor departure, a request for variation may be approved by the customer.
How do human factors influence systems engineering design?
In systems engineering the focus is to consider the human as an interfacing system that has certain characteristics and to incorporate consideration of those characteristics into the design of the rest of the system.
What are business constraints?
Includes any organisational policies, procedures, standards or guidelines that guide system development and procurement.
How is Innoslate different from ReqView?
Innoslate is referred to as "model-based systems engineering" or MBSE. It allows us to explore our requirements using different toolsets like models and simulation rather than being constrained by written requirements.
Testing is one method that may be used to perform verification. Other common methods include?
Inspection, analysis of previously collected data, and demonstration.
What is Configuration Management and how is it related to Systems Engineering?
Interweaved. Effect each other.
What is an Inspection?
Involves visual inspection of hardware and/or software (conformance against documentation).
Systems engineering is often described as a lifecycle discipline. Why is this important?
It ensures that system requirements and design are influenced by lifecycle issues such as production, utilisation and disposal.
How do you know who is involved in the verification program?
It must be clear which party, customer or supplier, is involved in the verification program and this is normally discussed in the relevant part of the contract Statement of Work (SOW).
What is N-type?
Multiple functionally equivalent programs are independently generated from the same initial specifications. Reduce the probability of identical software faults occurring in two or more versions of the program.
Who can carry out a use case correctly?
It takes training and experience to do use cases properly.
What is Rolling Wave Planning?
Iterative planning technique, near term planned in detail, future work planned at higher level.
What is Lead?
Lead is the amount of time; successor activity can be advanced with respect to a predecessor. - Negative value of lag (scheduling software). e.g. Finish Start (FS) 2 Weeks.
What are the CMMI Capability Levels? Why are they important?
Level 0 - Incomplete. Level 1 - Performed. Level 2 - Managed. Level 3 - Defined. Level 4 - Quantitatively Managed. Level 5 - Optimised. High-performing project-based organisations meet goals 2.5 times more often and waste 13 times less money than their low-performing counterparts.
What is the N-Version software development?
Multiple functionally equivalent programs are independently generated from the same initial specifications. Reduces the probability of identical software faults occurring in two or more versions of the program. Influences the engineering program SOW (Statement Of Work).
What is a Logistics Support Analysis Plan?
Outlines a roadmap plan for the entire lifecycle detailing what logistics support analysis will be performed and how it will be accomplished.
Keeping within the Design Space ensures?
Meet or exceeded all requirements.
What are the MOTS advantages?
Modified COTS items have the same advantages as COTS items. (tailor to specific need)
What is the Waterfall Development Model and when is it suitable?
One-way flow through the systems engineering process. Business value is delivered all at once - with the delivery of the system. Suitable when: - The requirements are knowable and known in advance of implementation. - The requirements have no unresolved, high-risk elements. - The nature of the requirements is stable. - The requirements are compatible with all the key stakeholders' expectations. - The right implementation architecture is well understood. - There is enough calendar time to proceed sequentially.
What systems is System Engineering applicable to?
Open, physical systems that are human-made/modified from largely precedented elements.
What are the life cycle activities that comprise the Utilisation Phase?
Operational Use and System Support.
Making optimal use of the available Design Space is the process of ensuring what?
Optimal system-level performance, and often requires sub-optimal subsystem-level performance.
What is the main purpose of Logistics Support Analysis?
Optimised system life cycle cost through an iterative, multi-disciplined process.
Other than a product, what else does a system include?
Organisation, personnel, collective training systems, facilities, data, support, and operating procedures and organisational policies.
Projects are not normally initiated and planned in a vacuum. What are the inputs?
Organisational and environmental factors.
What is the Incremental Development Model and when is it suitable?
Phased development of a known set of requirements. Multi-waterfall. Business value is delivered in phases. Suitable when: - Partial capability (builds) can be fielded and maintained. - Partial core capability is desired as early as possible. • Funding is phased - large initial outlay is avoided.
Given the Earned Value graph, how do you tell if the project is behind/ahead of schedule? Or if the project is under/over budget? What should be the course of action taken by the project manager?
Positive SV/CV means ahead schedule/under budget. Negative SV/CV means behind schedule/over budget. Take appropriate action to correct.
What is the document that is produced as a result of Detailed Design & Development?
Product Baseline (PBL).
What specifications does Detailed Design and Development produce?
Product Specifications. If hardware is to be produced and constructed, then Process Specifications and Material Specifications may also be required.
An organisation is reorganising to form a Project Management division. The boss asks you for Project Charter, why would you be happy about this?
Project Charter, authorises you to use organisational resources.
What is a Project management plan?
Project management plan is a formal approved document used to guide project execution, monitor and control.
What are TRR?
Test Readiness Reviews (TRR) are sometimes contractually required by the customer to demonstrate that the system CIs are ready to enter formal test and evaluation.
What is the Evolutionary Development Model and when is it suitable?
Refinement and discovery of requirements through phases. Business value is delivered progressively with backtracking possible. Suitable when: - Partial capability is needed and can be efficiently upgraded/maintained. - Initial usage of the system is expected to revise or discover requirements.
Joining the sets of requirements to the subsystems is done by what process?
Requirements allocation. Which represents the translation of functional design into physical design.
Requirements analysis and allocation is a key systems engineering activity in Preliminary Design. What is the process?
Requirements analysis takes the requirements in the SyRS and analysis them further to derive the requirements relevant at the subsystem- level. These requirements are then allocated to one or more of the subsystems via a requirements allocation matrix or equivalent. The result is a collection of subsystem specifications called 'Development Specifications' that are traceable to and from the SyRS and upon which preliminary design decision can be based.
In terms of risk treatment, what is diminishing rate of return?
Risk should be reduced to As Low As Reasonably Practical. As costs associated with risk treatment continue, as risk is progressively reduced less and less.
What is the Spiral Development Model and when is it suitable?
Risk-driven process model generator: - Iterates a set of elemental development processes to actively reduce risk. - Based on the unique risk patterns of a given project. - Guides a team to adopt elements of one or more process model.
System Design Reviews (SDR) are held near the end of Conceptual Design. What is a SDR?
SDR is a review involving both the Customer and the Contractor where the proposed system-level design is reviewed against its likely ability to meet specified system-level requirements.
What is the Scheduled Variance & Cost Variance equations?
SV = EV - PV. CV = EV - AC. Positive values are good. Ahead schedule & under budget.
What is the Schedule Performance Index & Cost Performance Index equations?
SV = EV/PV. CV = EV/AC.
What are Safety Integrity Levels?
Several industries have standards and mandatory procedures and for failure analysis notably automobiles, aircraft, medical devices. For example, ISO 26262 covers the functional safety of road vehicles. Note: Safety Integrity Levels (SILs) are often used in these standards to express the level of risk reduction required to prevent a specific hazard. A high SIL represents a high degree of hazard and high level of mandatory rigor to assure safety.
What is Schedule Compression?
Shorten the schedule without changing scope.
Why tailor systems engineering activities?
So that activities add value and reduce risks.
What is Resource Levelling?
Start & finish dates are adjusted based on resource constraints with goal of balancing demand.
What is the purpose of the Preliminary Design?
Starts with the Initial FBL from Conceptual Design and continues to translate system-level requirements into design requirements for the system elements that will combine to form the system.
In Preliminary Design, the subsystems are being designed and this process almost always involves identifying and considering subsystem-level interfaces. What should happen with Subsystem-level interfaces?
Subsystem-level interfaces must be identified and document as they place additional requirements/constraints on our interfacing subsystems. Interface requirements can be captured in the relevant Development Specifications or in a dedicated interface Control Document, but they need to be mutually agreed between the 'owners' of the respective subsystems.
Innoslate is based on a combination of what?
SysML, LML and Requirements View.
What is conducted at the end of Conceptual Design? What does it provide?
System Design Review (SDR): - logical design meets business and stakeholder requirements. - record of design decisions and acceptance. - communication of the intended design approach to major players in design effort. - approval of the V&V plans. - approval of the Systems Engineering Management Plan (SEMP).
How is the data captured for technical metrics?
Technical metrics evolve as system development progresses. If weight is a technical metric, then only the hardware elements of the design will contribute so we need to see how system weight is allocated (or not allocated) to subsystems, CIs and components. We then make sure that as the technical metrics are allocated, so too is the need to monitor those allocated parameters. Requirements traceability can help here.
Other than risky parameters, what parameters could be used in technical metrics?
Technical metrics may not be risky parameters but may be parameters that provide insight into the progress of the technical program (eg latency in a real-time system may provide some insight into progress in areas of concern such as software development etc).
How is the Technical metrics program formed?
Technical metrics will be generated by both the customer and the supplier and the two perspectives are complementary. Collaboration on the technical metrics program is valuable.
What is an example of System-level synthesis?
Tender negotiation.
What do Measures Of Effectiveness (MOE) relate?
The next level of the requirements hierarchy.
What is the definition of Configuration?
The complete technical description required to fabricate, test, accept, operate, maintain, and logistically support equipment.
What is the aim of the Detailed Design?
The detailed design effort takes these definitions of the overall system, as contained in the FBL, (Conceptual Design) and of the major CIs, contained in the ABL, (Preliminary Design) and finalises the design of specific components that make up the CIs (and subsystems).
What is produced as a result of the Preliminary Design effort?
The establishment of an Allocated Baseline (ABL), in which requirements are 'allocated' to specific physical system elements that combine to form the system.
Production planning is critical and is continually reviewed and updated as the system design matures. What is the relationship between design and production planning?
The evolving design is a key input to the production planning process to ensure that our production system can be adjusted to take account of our design. However, our current or projected production capability is also a key input into the design process. This helps us come up with design options that meet requirements but can be cost-effectively produced using our expected production capability.
Other than life-cycle cost analysis, what is the key concept of LSA?
The key concepts of LSA are system availability and life-cycle cost analysis. System availability is impacted by failure rates and repair/replacement times. System availability can be achieved in many ways and the efficacy of each alternative should be compared using a life-cycle costing model.
What is the difference between maintenance system and FRACAS?
The maintenance system rectifies the failure and the FRACAS attempts to rectify the cause.
What do Critical Operational Issues (COI) relate?
The measurement of objectives.
What do Critical Issues (CI) relate?
The measurement of system goals.
What do Measures Of Performance (MOP) relate?
The next level down, of the requirements hierarchy from MOE.
How does the PMBOK divide the major parts of Projects?
There in Process groups not project phases.
What artefacts are produced as a result of verification?
There is a hierarchy of verification formal artefacts; verification concept, Verification plans, Verification procedures, Test Cases and Verification Results.
What features do ReqView & Innoslate have?
These sorts of tools have features like automatic document production, import/export features, and traceability features and can therefore really help when we are dealing with large numbers of inter-related requirements.
What can ReqView & Innoslate offer system engineering?
These tools help with the requirements management piece of systems engineering - requirements elicitation, requirements analysis, requirements quality checks, traceability, verification and change management.
Can ReqView & Innoslate automatically generate and guarantee perfect requirements?
These tools still require expertise to get the job done properly. It is not a case of complete automation. It is a case of quality in, equals quality out.
Why is it important to standardise the structured language that is formed from the use case's system-in-use-story?
This structured language is standardised to provide a foundation for other modelling and analysis processes and so that developers can estimate the scale of the system. There is a technique called use-case point counting that gives a reasonable preliminary estimate of software development effort. This can only be done if standards apply. For example, each line of the use case must be a transaction that leaves the system in an internally consistent state.
What is a Review?
Typically design documentation and drawings
What is the aim of use cases?
Use cases bridge the system user (business sponsor) world to the systems engineering world.
Technical metrics allow a systems engineer to?
Use multiple data sets that potentially indicate project problems and concerns and start the mitigation process earlier. (NEED TO CHECK ANSWER WITH GROUP 3)
Why identify safety-significant functions (SSF)?
identify SSF and safety related considerations early, then we can influence the subsequent requirements analysis and design (when it is cheapest and easiest to influence the design - early!).
