Design and Implementation of Correct Efficient and Maintainable Programs?

The  entire program or software (collection of programs) development process is divided in to a number of phases, where each phase performs a well- defined task .

                                                 

                                                  Phases in  Software development

                                                              Life cycle.

Requirements analysis:

 in this phase , the user’s expectations are gathered to understand why the program or software has to be developed. Then , all the gathered requirements are analysed  and the scope or objective of the over all software product is penned down. The last activity in this phase involves documenting every identified requirement of the user in order to avoid any doubts or uncertainty regarding the functionality of the program. The functionality, capability, performance, and availability of hardware and software components are all analysed in this phase.

Design:

The requirement documented in the previous phase act as the input to the design phase. In this phase, a plan of actions is made before the actual development process starts. This plan will be followed throughout  the development process. Moreover, in the design phase, the core structure of the software or program is broken down in to modules. The solution of the program is then specified for each module in the form of algorithms or flow charts . The design phase, therefore specifies how the program or software will be developed.

Implementation:

In this phase, the designed algorithms are converted in to program code using any of the high level languages. The particular choice of language will depend on the type of program such as whether it is a system or an application program. C is preferred for writing system programs, whereas Visual basic might be preferred for an application program. The program codes are tested by the programmer to ensure their correctness.

Testing:

In this phase , all the modules are tested together to ensure that the overall system works well as a whole product. In this phase, the software is tested using a large number of varied inputs, also known as test data, to ensure that the software is working as expected by the user’s requirements identified in the requirements analysis phase.

Software deployment, training, and support:

After the code is tested and the software or the program is approved by the user’s it is then installed or deployed in the production environment.

Software training and support is a crucial phase. Program designers and developers spend a lot of time creating the software, but if nobody in the organization knows how to use it or to fix certain problems , then no one will want to use it.

Maintenance:

Maintenance and enhancements are ongoing activities that are done to cope with newly discovered problems or new requirements. Such activities may take a long time to complete.