System Development
Data analysis: As we are living in the “Informationage” so it is generally believed in today’s computing scenario that data or information is the most precious commodity. Therefore, data must be accurate. Complete, and readily available in the systems we design. So to keep it in proper shape, we have many tools available. For example: DFDs (Data Flow Diagrams), system flowcharts, connectivity Diagrams, Grid charts, and Decision Tables etc. it is beyond the scope of this course to discuss them in details here.
Analysis Report: once the analysis work is over, we need to document it in a presentable form to the higher management for their review and approval of the project. This report should have three parts: First, it should explain how the current system (manual or automated if exists) works. Second, it should explain the problems in the existing system, and finally it should describe the requirements for the new system and make recommendations for future.
Design: in this phase of SDLC, the analyst works on the preliminary (Logical) design, detail (physical) design, and then writes a detailed report.
- Logical design: it describes the general functional capabilities of a proposed system. It reviews the system requirements and considers the major system components. Case tools and project management software (MS-Project, Gantt chart, PERT chart etc) may be used to accomplish this task. You will learn about these tools and software in some advanced course.
- Physical design: it describes how a proposed system will deliver the general capabilities described in the Logical design. It will address the following points: output requirements, input requirements, storage requirements, processing requirements, and system control and backup/recovery.
- Report: a detailed report on logical, physical design is to be submitted to the higher management along with some sort of presentation, explaining them the details of the proposed system.
Coding: This is the core area of the system development process. It consists of writing the segments and programs, which will be coupled together in the shape of a complete system. It needs a lot of time, effort and budget to acquire a workable system. The program specifications, algorithms, flowcharts are given to the programmers/ software engineers to code the required programs. Off-the-Shelf-Components (already written programs) can also be used and embedded in the system to save time and effort.
Testing: Having proper hardware acquired, the programs can be tested in two stages:
- Unit-testing: it is also called modular testing where individual modules, programs can be tested using test (sample) data.
- System-testing: in this, parts or modules are linked together to test their workability as a one system. Actual data may be used to do the system testing and at the same time, erroneous data can also be used to check whether the system fails or not.
Id the system passes all the tests, we can implement the system on the servers, so that the organization and other clients can use it.
Implementation: this activity consists of transferring the hardware, software and data (files, database etc) to the new working environment (server). Users of the system are also trained in this phase. Implementation may be achieved in five steps:
- Direct implementation: in this way, the users start using the new system right away and stop working on the old one.
- Parallel implementation: Using this approach, the new and old systems are used side by side until it is felt that the new system is quite reliable.
- Phased Implementation: in this approach, the new and old systems are used side by side until it is felt that the new system is quite reliable.
- Pilot Implementation: this type of implementation allows us to implement the complete system but to a selected group of users or selected departments.
- Users Training: involving the users in the SDLC process from the beginning and ensuring their proper training is very much essential throughout the system design activity. A variety of methods/ tools are used to do so i.e. Instruction Manual, Videotapes/CDs, and lectures etc. the training may be conducted “in-house” or it may be “Contracted Out”.
| Comment: in general, the pilot and phased implementation are the most favored and popular approaches to implement the systems. Phased approach is preferable for organizations where different types of functions are carried out whereas Pilot approach is preferred where almost same type of work is going on in the organization. |
Maintenance: the last phase adjusts and improves the system by considering the users evaluation, feedback, and enhancements based on their due recommendations. In this phase, due maintenance and help is also provided to the users against their queries, problems, and ambiguities.
