Ch. 12-4 What are the Phases in the Systems Development Life Cycle (SDLC)?
Organizational feasibility
whether the new system fits within the org's customs, culture, charter, or legal requirements
Maintaining systems details
work done during this phase is either to fix the system so that it works correctly or to adapt it to changes in requirements
Cost feasibility
an assessment of whether the anticipated benefits of the system are likely to justify the estimated development and operational costs, whether the project can realistically be done within the budget provided
5 phase process
define system (project plan); determine requirements (approved requirements); design system components (system design); implement system (information system → system users → problem or need for change); maintain system
Steps in defining the system
define system goals and scope (development team defines the goal and purpose of new system in terms of how it will facilitate an org's competitive strategy by improving the quality of business processes); assess feasibility (has 4 dimensions- cost, schedule, technical, and organizational feasibility); form a project team (Team consists of both IS professionals and user representatives; user involvement is critical throughout process)
Requirements analysis
developers identify the particular features and functions of the new system; output of this phase is a set of approved user requirements which become the primary input used to design system components
Implement system
developers implement, test, and install the new system
Details of determining requirements
most important phase in SDLC process; Requirements include what is to be produced and how frequently and how fast it should be done; Conduct user interviews; Evaluate existing systems and features and functions desired in new system; Consider security requirements; build prototype; get requirements approved by users
Phased installation
new system installed in phases across the org as each piece succeeds
Parallel installation
new system runs parallel with the old one until the new system is tested and fully operational; expensive to run both systems at the same time
Pilot conversion
org implements the entire system/business process on a limited portion of the business; contains possible failures
Plunge installation
org shuts off old system and starts the new one; avoid this to avoid processes and org failing
Maintain system
overtime users find errors, problems, will develop new requirements; description of fixes and new requirements is input into a system maintenance phase that starts the cycle all over
Role of a prototype
provides direct experience for users; Users will remember forgotten features/functions; Provides evidence to assess the system's tech and org feasibility; Create data that can be used to estimate development and operational costs; Parts of prototype can often be reused in operational system
Technical feasibility
refers to whether existing information technology is likely to be able to meet the needs of the new system
Schedule feasibility
rough estimate of time it will take to develop system and put it into operation, min. schedule
Systems development life cycle (SDLC)
the traditional process used to develop information systems and applications
System implementation details
to build and test system components and to convert users to the new system and possibly new business processes; entire system tested as an integrated whole after each component has been tested individually; system conversion of business activity from the old system to the new (4 types of conversion: pilot, phased, parallel, plunge)
Define system
use management's statement of the system needs in order to begin to define the new system; results in a project plan that leads to the input for the next phase
