Systems Analysis and Design
horizontal system
A basic system, such as an inventory or payroll package that is commonly used by a variety of companies.
System Request
A formal request to the IT department that describes problems or desired changes in an information system or business process. It might propose enhancements for an existing system, the correction of problems, or the development of an entirely new system.
server farm
A large concentration of servers working together
Economic Feasibility
A process of identifying the financial benefits and costs associated with a development project.
mission-critical system
An information system that is vital to a company's operations.
Transaction Processing System (TPS)
Basic business system that serves the operational level and assists in making structured decisions
System Implementation phase
During this phase the new system is constructed, programs are written, tested, and documented, and the system is installed
System planning phase
During this phase the systems project gets started. The project proposal is evaluated to determine its feasibility. The project management plan is formulated, with the help of CASE tools where appropriate
Enterprise Applications
Include order processing systems, payroll systems, and company communications networks
project creep
Projects with very general scope definitions are at risk of expanding gradually, without specific authorization
Scalability
Refers to a system's ability to handle increased volume and transactions in the future
Business Case
Refers to the reasons, or justification, for a proposal.
systems requirements document
The end product of the SDLC systems analysis phase
System Development Life Cycle (SDLC)
The overall process for developing information systems from planning and analysis through implementation and maintenance
System Design Phase
The purpose of systems design is to create a blueprint for the new system that will satisfy all documented requirements, whether the system is being developed in-house or purchased as a package
System Analysis Phase
The purpose of this phase is to build a logical model of the new system
system requirement
a characteristic or feature that must be included in an information system to satisfy business requirements and be acceptable to users
data flow
a path for data to move from one part of the information system to another
Entity
a rectangle, which may be shaded to make it look three-dimensional
constratint
a requirement or condition that the system must satisfy or an outcome that the system must achieve
Systen
a set of related components that produces specific results
Business process
a specific set of transactions, events, and results that can be described and documented
Systems Analysis and Design
a step-by step process for developing high-quality information systems
Enterprise Resource Planning (ERP)
a suite of applications called modules, a database, and a set of inherent processes for consolidating business operations into a single, consistent, computing platform
system analyst
a valued member of the IT department team who helps plan, develop, and maintain information systems
Fishbone diagram
a visual aid that helps organize cause and effect relationships for "things gone wrong"
Physical Model
built that describes how the system will be constructed
Information System
combines technology, people, and data to provide support for business functions such as order processing, inventory control, human resources, accounting, and many more
Hardware
consists of everything in the physical layer of the information system.
Application Software
consists of programs that support day-to-day business functions and provide users with the information they need
Project scope
defining the specific boundaries, or extent, of the project
Processes
describe the tasks and business functions that users, managers, and IT staff members perform to achieve specific results.
vertical system
designed to meet the unique requirements of a specific business or industry, such as an online retailer, a medical practice, or an auto dealership
feasibility study
investigation that gauges the probability of success of a proposed project and provides a rough assessment of the project's feasibility
system software
manages the hardware components, which can include a single computer or a global network with many thousands of clients
schedule feasibility
means that a project can be implemented in an acceptable time frame
Legacy systems
older information systems that remain in use because they still function and are costly to replace
Business Support Systems
provide job-related information support to users at all levels of a company
Output
refers to electronic or printed information produced by the system
secuirty
refers to hardware, software, and procedural controls that safeguard and protect the system and its data from internal or external threats
enterprise computing
refers to information systems that support company-wide operations and data management requirements.
Input
refers to necessary data that enters the system, either manually or in an automated manner
Performance
refers to system characteristics, such as speed, volume, capacity, availability, and reliability.
information technology
refers to the combination of hardware, software, and services that people use to manage, communicate, and share information.
Process
refers to the logical rules that are applied to transform the data into meaningful information
Technical Feasibility
refers to the technical resources needed to develop, purchase, install, or operate the system
Logical model
shows what the system must do, regardless of how it will be implemented physically
Electronic Data Interchange (EDI)
the computer-to-computer exchange of business documents from a retailer to a vendor and back
software
the programs that control the hardware and produce the desired information or results
Data store
used in a DFD to represent data that the system stores because one or more processes need to use the data at a later time
Required modeling
where the analyst investigates business processes and documents what the new system must do to satisfy users