Presentation on theme: "Chapter 12 Systems Development Three common methods for MIS development: The systems development life cycle (SDLC) Prototyping End-user development Five."— Presentation transcript:
Chapter 12 Systems Development Three common methods for MIS development: The systems development life cycle (SDLC) Prototyping End-user development Five phases for MIS development (p.465) Feasibility and planning Systems analysis Systems design Implementation Maintenance and Review
I. The systems development life cycle (SDLC) 1. Why SDLC (p.464) The need for control. The problems lead to runaway projects: – Coordinate programmers and analysts, and avoid duplicated efforts – Late project and over budget – Employee turnover – Specifications changed by users – Compatibility of subsystems Therefore, it is important to establish procedures and standards for everyone to follow. The need for planning - Goals, Milestones, Time and Cost.
2. Five major phases of SDLC Feasibility and planning (p.466) –Feasibility: problems, goals and costs. Alternatives? Worth doing? –Planning: Schedules, milestones and MIS team leaders. Systems analysis (p.466) –Interview users –Describe existing system (e.g., DFD p.478) –Divide it into subsystems, processes and activities (e.g., DFD) –Identify problems
Systems design (p.467) – Involve users – Describe new system (e.g., DFD) – Describe new system: subsystems, databases, processes, reports, windows, and so on. – Requirements and specifications. Requirements for system outputs such as statements of what system should do or example of output forms (i.e., invoices, order sheets, “wish list”, and so on). – Management sign off. – Physical design: hardware, software, write and test codes (e.g., Access database application). – Test: prototype and structured walkthrough. – Output of design: complete technical specification.
Systems implementation (p.468) – Involve users – Final test and install new system – Convert data (e.g., Excel to Access) – Training – Understand effect of new system on business – Implementation plans such as direct cutout, parallel, pilot and phased. – Switch from the old system to the new one Maintenance and Review (p.470) – Maintenance: business change, hardware upgrades, software upgrades, specification changes, and user turnover. – Evaluation (Figure 12.6): feasibility (costs, time, revenue, goals, user satisfaction), and system performance.
3. Advantages and disadvantages of SDLC (p.471) Advantages – User involvement – Control and monitor large project – Detailed steps and schedules for fast development – Documentation and standards – Ease of maintenance and modification Disadvantages – Not really control time and budget – More time spent on management rather than the system – Beyond certain stage, user involvement is limited.
II. Prototyping 1. Why Prototyping (p.472) Suitable for small projects used by fewer users. Suitable for projects when users have difficulty to describe what they exactly want beforehand. The working system can be received in a short time by using a fourth-generation language and a DBMS. Therefore, users can work with the prototype and suggest changes. Developers and users repeat a cycle “new version - use prototype - request changes - modify prototype” until the users are satisfied or discard the project.
2. Advantages of Prototyping (p.473) The working system can be received in a short time. More input from users even though they have difficulty to describe what they exactly want beforehand. Easy to change. A prototype may not have many codes. It may be a collection of input windows and output reports so users can see what they can get from the system. 3. Disadvantages of Prototyping Different changes wanted by users. (Solution: multiple prototypes.) When to stop the cycle. (Solution: managers stop trivial changes.)
III. End-User Development 1. Why End-User Development (p.475) Backlog of MIS projects. Available powerful and easy to use software tools. Suitable for small projects that involves user’s expertise. Suitable for projects that support one-time decision- making. Suitable for projects that can be completed by using off-shelf software, e.g., Excel and Access.
2. Advantages of End-User Development Fast. Best address user’s needs. 3. Disadvantages of End-User Development Not for multiple users. No complete document. Lack of security control. Lack of testing. Lack of standards and compatibility. Difficult to modify and grow. Take user’s time. Limitations of commercial software.