Mid term
DFD Completeness
DFD must include all components necessary for system. Each component must be fully described in the project dictionary or CASE repository.
Ways of Assessing Project Feasibility
Economic Technical Operational Scheduling Legal and contractual Political
Written work procedure
For an individual or work group Describes how a particular job or task is performed Includes data and information used and created in the process
Name the 6 Sources of Software
Information technology services firm Packaged software producers Enterprise solutions software Enterprise Resource Planning (ERP) Cloud computing Open source software In-house developers
4 methods for determining requirements
Interviewing individuals Interviewing groups Observing workers Studying business documents
System prototypes
Iterative development process Rudimentary working version of system is built Refine understanding of system requirements in concrete terms
Interviewing Groups Disadvantage
More difficult to schedule than individual interviews
Interviewing Groups Advantages
More effective use of time Can hear agreements and disagreements at once Opportunity for synergies
Report
Primary output of current system Enables you to work backwards from the report to the data needed to generate it
Data Flow Diagramming Mechanics characteristics
Represent both physical and logical information systems Only four symbols are used Useful for depicting purely logical information flows
DFD Timing
Time is not represented well on DFDs. Best to draw DFDs as if the system has never started and will never stop
Business form
Used for all types of business functions Explicitly indicates what data flow in and out of a system and data necessary for the system to function Gives crucial information about the nature of the organization
CASE tools
Used to analyze existing systems Help discover requirements to meet changing business conditions
Information Sources For RFP
Vendor's proposal Running software through a series of tests Feedback from other users of the vendor's product Independent software testing services Customer surveys Articles in trade publications are sometimes biased (seeded by manufacturer)
Direct Observation
Watching users do their jobs Used to obtain more firsthand and objective measures of employee interaction with information systems Can cause people to change their normal operating behavior Time-consuming and limited time to observe
an Activity
a behavior that an object carries out while in a particular state represented by a sold circle with arrow attached to the bottom
Data store
data at rest (inside the system)
What are the 2 DFD guidelines
1. The inputs to a process are different from the outputs of that process 2. Objects on a DFD have unique names
1980s
4GL, CASE tools, objectoriented methods
4 Approaches to reuse
Ad-hoc Facilitated Managed Designed
3 Different Approaches to Improving Development
CASE Tools Agile Methodologies eXtreme Programming
Drawbacks to individual interviews
Contradictions and inconsistencies Follow-up discussions are time consuming may reveal new questions that require additional interviews
3 Principles of Agile Methodologies
Adaptive rather than predictive Emphasize people rather than roles Self-adaptive processes
The heart of systems development
Analysis, design and implementation
DFD Iterative Development
Analyst should expect to redraw diagram several times before reaching the closest approximation to the system being modeled.
________ is designed to support organizational functions or processes.
Application software
"What of the following is NOT a consequence of employees knowing they are being observed in their work?"
Employees may miss work.
Operational feasibility deals with project duration.
FALSE
Which of the following is NOT a factor in determining legal and contractual feasibility?
Financial budgets
Object-Oriented Analysis and Design
Based on objects rather than data or processes
"The overall process by which current methods are replaced with new methods is referred to as ________."
Business process re-engineering
Open Source Software
Freely available including source code Developed by a community of interested people Performs the same functions as commercial software Examples: Linux, MySQL, Firefox
Information Technology Services Firms
Help companies develop custom information systems for internal use
In-House Development
If sufficient system development expertise with the chosen platform exists in-house, then some or all of the system can be developed by the organization's own staff
"Which of the following is an organization that hosts and runs computer applications for other companies, typically on a per use or license basis?"
Cloud computing application provider
Which of the following are delivered after the completion of the implementation phase?
Code, documentation, training procedures, and support capabilities
3 Advantages of eXtreme Programming
Communication between developers High level of productivity High-quality code
Information Systems Analysis and Design
Complex organizational process Used to develop and maintain computer-based information systems
A case model
Consists of actors and use cases
"A ________ can be best understood as data in motion, moving from one place in a system to another."
Data flow
________ are NOT a component of data flow diagram symbols.
Data programs
Elements of Project Planning
Describe project scope, alternatives, feasibility
Written Use Cases contain
Detailed, Step-by-step description of what must occur in a successful use case
Computer-Aided Software Engineering (CASE) Tools
Diagramming tools enable graphical representation. Prototype look and feel of system
Which of the following is NOT a useful document in the analysis process?
E-mails
Which feasibility category deals with identifying financial benefits associated with the project?
Economic
New Logical
Includes additional functions Obsolete functions are removed. Inefficient data flows are reorganized.
3 Contemporary Methods for Determining System Requirements
Joint Application Design (JAD) CASE tools System prototypes
Business Case
Justification for an information system Presented in terms of the tangible and intangible economic benefits and costs The technical and organizational feasibility of the proposed system
Throwaway prototyping
Prototype is just a mockup and just a model, discarded after use
Evolutionary prototyping
Prototype needs to be built and becomes the basis of the operational system
Which tool enables you to quickly take basic requirements and create a limited working system?
Prototyping
Packaged Software Producers
Provide software ranging from broad-based packages (i.e. general ledger) to niche packages (i.e. day care management) Pre-packaged, off-the-shelf software
All of the following are documents that are helpful in understanding future systems, except ________.
Reports from future organizational studies
New Physical
Represents the physical implementation of the new system
The following is NOT an example of a type of feasibility study.
Resource feasibility
Document Analysis
Review of existing business documents Can give a historical and "formal" view of system requirements
eXtreme Programming
Short, incremental development cycles Automated tests Two-person programming teams
Activity Diagrams
Show the conditional logic for the sequence of system activities needed to accomplish a business process. Clearly show parallel and alternative behaviors. Can be used to show the logic of a use case
Drawbacks of Prototyping during requirements determination
Tendency to avoid formal documentation Difficult to adapt to more general user audience Sharing data with other systems is often not considered Systems Development Life Cycle (SDLC) checks are often bypassed
Reuse
The use of previously written software resources, especially objects and components, in new applications.
Systems Development Life Cycle (SDLC)
Traditional methodology used to develop, maintain, and replace information systems
"A use-case consists of a set of possible sequences of interactions between a system and ________ in a particular environment, possible sequences that are related to a particular goal."
User
Which of the following is a drawback of the traditional waterfall SDLC approach?
Users are locked into requirements.
Present Day
Web application development, wireless PDAs and smart phones, component-based applications, peruse cloud-based application services.
Rules for Stopping DFD Decomposition
When each process has been reduced to a single decision, calculation or database operation When each data store represents data about a single entity When the system user does not care to see any more detail
"CASE helps programmers and analysts do their jobs more efficiently and more effectively by automating routine tasks."
When they contain organizational data
a Branch
a diamond symbol containing a condition whose results provide transitions to different paths of activities represented by a diamond with 2 arrows pointing out
Object class
a logical grouping of objects sharing the same attributes and behaviors
Use case diagram
a picture showing system behavior along with the key actors that interact with the system
Economic feasibility or cost-benefit analysis
a process of identifying the financial benefits and costs associated with a development project
Object
a structure encapsulating attributes and behaviors of a real-world entity
a Merge
a symbol where different branches converge represented by a diamond with 2 arrows pointing in
Project initiation focuses on
activities designed to assist in organizing a team to conduct project planning
Prototyping
an iterative process of systems development in which requirements are converted to a working system that is continually revised through close collaboration between an analyst and users.
Planning
an organization's total information system needs are identified, analyzed, prioritized, and arranged
Intangible benefits a
benefits derived from the creation of an information system that cannot be easily measured in dollars or with certainty. Ex: improved morale
Joint Application Design (JAD)
collect system requirements simultaneously from key people Brings together key users, managers, and systems analysts
Swim lanes
columns representing different organizational units or functions of the system
Tangible cost
cost associated with an information system that can be measured in dollars and with certainty ex: Hardware costs Labor costs, or Operational costs, including employee training and building renovations.
Intangible cost
cost associated with an information system that cannot be easily measured in terms of dollars or with certainty ex: Loss of customer goodwill, Employee morale, or Operational inefficiency.
One-time cost:
cost associated with project start-up and development or system start-up ex: user training site preparation system development
Recurring cost
cost resulting from the ongoing evolution and use of a system Application software maintenance Incremental data storage expenses Incremental communications New software and hardware leases, and Supplies and other expenses (i.e., paper, forms, data center personnel)
Present value
current value of a future cash flow
1950s
efficient automation of existing processes
Logical design
features of the system chosen for development in analysis are described independently of any computer platform
Inheritance
hierarchical arrangement of classes enable subclasses to inherit properties of superclasses
Implementation
information system is coded, tested, installed and supported in the organization
Maintenance
information system is systematically repaired and improved
Enterprise Resource Planning (ERP)
integrate individual traditional business functions into modules enabling a single seamless transaction to cut across functional boundaries.
interview guide
is a document for developing, planning and conducting an interview.
Primitive DFD
is the lowest level of a DFD.
Physical design
logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished
Time value of money (TVM)
money available today is worth more than the same amount tomorrow
Systems Analyst
most responsible for analysis and design of information systems
Outsourcing
practice of turning over responsibility of some or all of an organization's information systems applications and operations to an outside firm
Technical feasibility
process of assessing the development organization's ability to construct a proposed system
Discount rate
rate of return used to compute the present value of future cash flows
Design
recommended solution is converted into logical and then physical system specifications
Tangible benefits
refer to items that can be measured in dollars and with certainty Examples include: reduced personnel expenses lower transaction costs, or higher profit margins.
Level-1 diagram
results from decomposition of Level-0 diagram.
Application Software
software designed to support organizational functions or processes
System Development Methodology
standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems.
1970s
system development becomes more like an engineering discipline
1990s
system integration, GUI applications, client/server platforms, Internet
Analysis
system requirements are studied and structured
a Fork
the beginning of parallel activities represented by a line with 2 arrows pointing out
a Join
the end of parallel activities represented by 2 arrows pointing to a horizontal line
Formal Systems
the official way a system works as described in organizational documentation (i.e. work procedure)
Informal Systems
the way a system actually works (i.e. interviews, observations)
1960s
third generation languages (3GL) faster and more reliable computers
Abstract use case
when a use case is initiated by another use case
Process
work or actions performed on data (inside the system)
"A ________ is a DFD that represents a system's major processes, data flows, and data stores at a high level."
Level-0 diagram
"Balancing is the conservation of inputs and outputs to a DFD process when that process is decomposed to a ________ level."
Lower
Agile Methodologies
Motivated by recognition of software development as fluid, unpredictable, and dynamic
A logical grouping of objects that have the same attributes and behaviors is known as a(n) ________.
Object class
Reuse is commonly applied to
Object-oriented development and Component-based development
Which feasibility is concerned with the project attaining its desired objectives?
Operational feasibility
"No process can have only ________. It would be making data from nothing. If an object has only that, then it must be a source."
Outputs
What is the practice of a company running a computer application for another organization?
Outsourcing
5 Phases in SDLC:
Planning Analysis Design Implementation Maintenance
The lowest level of a DFD is called a ________ data flow diagram.
Primitive
"A ________ is the work or actions performed on data so that they are transformed, stored, or distributed."
Process
Data cannot move directly from one data store to another data store. Data must be moved by a
Process
Current Physical
Process labels identify technology (people or systems) used to process the data. Data flows and data stores identify actual name of the physical media.
Current Logical
Physical aspects of system are removed as much as possible. Current system is reduced to data and processes that transform them.
System boundary
- Includes all the relevant use cases A boundary is the dividing line between the system and its environment Use cases are within the boundary Actors are outside of the boundary Represented as a box
Actor
- Is a role, not an individual Involved with the functioning of the system at some basic level Represented by stick figures
Use case
- represents a single system function - Represented as an ellipse
Name the 4 types of DFDs
Current Physical Current Logical New Logical New Physical
"________ solutions integrate individual traditional business functions into a series of modules so that a single transaction occurs seamlessly within a single information system rather than several separate systems."
ERP
Which of the below is NOT a true statement regarding the SDLC?
It is a rapid method to prototype and develop an application.
"Functional decomposition is a(n) ________ process of breaking the description of a system down into finer and finer detail, which creates a set of charts in which one process on a given chart is explained in greater detail on another chart."
Iterative
In which phase of the SDLC is an information system systematically repaired and improved?
Maintenance
Which of the following is NOT a source of requirements gathering for the systems analyst?
Market conditions
A DFD Diagram is balanced when
Number of inputs to lower level DFD equals number of inputs to associated process of higher-level DFD Number of outputs to lower level DFD equals number of outputs to associated process of higher-level DFD
"Systems development methodologies and techniques which are based on objects rather than data or processes are known as"
Object-oriented analysis and design
Which of the following is NOT a major category of sources of software?
Offshore
"A data flow cannot go directly back to the same process it leaves. There must be at least _______ other process(es) that handle(s) the data flow, produce(s) some other data flow, and return(s) the original data flow to the beginning process."
One
"If a company has a generic software need, they should consider acquiring its software from a(n) ________."
Packaged software producer
"In which design phase of the SDLC are logical specifications of the system from logical design transformed into technology-specific details from which all programming and system construction can be accomplished?"
Physical design
What is the first phase in the Systems Development Life Cycle?
Planning
The document sent to vendors asking them to propose hardware and software that will meet the requirements of your new system is called a
Request for proposal
"________ refers to the use of previously written software resources, especially objects and components, in new applications."
Reuse
Which type of feasibility deals with project duration?
Schedule feasibility
All of the following are categories of feasibility except ________.
Scope
"A ________ is the origin and/or destination of the data, and these are sometimes referred to as external entities because they are outside the system."
Source/Sink
Which of the following is NOT a consideration during the assessing technical feasibility stage?
System cost
Who has the primary responsibility for the design and analysis of information systems?
Systems analyst
"Most organizations find it beneficial to use a standard set of steps, called ________, to develop and support their information systems."
Systems development methodology
"A data flow is data that move together, so it can be composed of many individual pieces of data that are generated at the same time and that flow together to common destinations."
TRUE
"Although almost all systems development projects adhere to some type of life cycle, the exact location of activities and the specific sequencing of steps can vary greatly from one project to the next."
TRUE
"Computer-aided software engineering (CASE) tools were developed to make systems developers' work easier and more consistent."
TRUE
"Finding and fixing a software problem after the delivery of the system is often far more expensive than finding and fixing it during analysis and design."
TRUE
"The part of the design process that is independent of any specific hardware or software platform is referred to as logical design."
TRUE
Sources/sinks are sometimes referred to as external entities because they are outside the system.
TRUE
DFDs of new logical system are
Technology independent Show data flows, structure, and functional requirements of new system
When are forms most useful to the analyst?
When they contain organizational data
Data flow
arrows depicting movement of data
Balancing
conservation of inputs and outputs to a data flow diagram process when that process is decomposed to a lower level
Conservation Principle
conserve inputs and outputs to a process at the next level of decomposition
Source/sink
external entity that is the origin or destination of data (outside the system)
Level-n diagram
is a DFD diagram that is the result of n nested decompositions from a process on a level-0 diagram.
Level-0 diagram
is a data flow diagram that represents a system's major processes, data flows, and data stores at a high level of detail.
Extend relationship
is an association between two use cases where one adds new behaviors or actions to the other. Extends a use case by adding new behavior or actions Specialized use case extends the general use case.
Include relationship
is an association between two use cases where one use case uses the functionality contained in the other. Indicates a use case that is used (invoked) by another use case Links to general purpose functions, used by many other use cases
Connection
is an association between an actor and a use case. Depicts a usage relationship Connection does not indicate data flow Actors are connected to use cases with lines. Use cases are connected to each other with arrows.
Context diagram
is an overview of an organizational system that shows: the system boundaries external entities that interact with the system major information flows between the entities and the system Note: only one process symbol, and no data stores are shown
Data flow splitting
is when a composite data flow at a higher level is split and different parts go to different processes in the lower level DFD.
A Context data flow diagram (DFD) deliverable is
The Scope
The first page of the interview guide contains all of the following except ________.
The outcome of the interview
Cloud Computing
The provision of computing resources, including applications, over the Internet, so customers do not have to invest in the computing infrastructure needed to run and maintain the resources ex: google doc
"A(n) ________ is an external entity that interacts with a system and is someone or something that exchanges information with the systems."
Actor
In which phase of the SDLC are the system requirements studied and structured?
Analysis
"A data flow has a noun phrase label. More than one data flow noun phrase can appear on a single ________ as long as all of the flows on the same arrow move together as one package."
Arrow
According to the DFD conventions, the data flow is always depicted by a(n) ________.
Arrow
All of the following are ways of validating purchased software information, except
Asking the manufacturer if they feel their software is best
Use case
Is a depiction of a system's behavior or functionality under various conditions as the system responds to requests from users
What do DFDs of current systems do
Enable analysts to understand current logical and physical systems
Which of the following is an example of a tangible benefit?
Error reduction in data entry
Which of the following is NOT an example of open-source software?
Excel
"DFDs do a very good job of representing time. On a given DFD, there is an indication of whether a data flow occurs constantly in real time, once per week, or once per year. There is also an indication of when a system would run."
FALSE
Implementation is the final step of the traditional waterfall SDLC method.
FALSE
Process Modeling
Graphically represent the processes that capture, manipulate, store, and distribute data between a system and its environment and among system components. Utilize information gathered during requirements determination. Model processes and data structures.
"In which phase of the SDLC is the information system coded, tested, installed, and supported in the organization?"
Implementation
How does an organization rank criteria for choosing off the shelf software?
Importance depends on the organization's requirements.
"When an organization has the resources and a system must be built from scratch, an organization should choose what type of software?"
In-house development
"A(n) ________ arises when one use case uses another use case and is shown diagrammatically as a dotted-line arrow pointed toward the use case that is being used."
Include relationship
No process can have only ________ and if an object has only that, then it must be a sink.
Inputs
