The second stage is implementation. This is where the software engineers use the scope document to begin writing the code that forms the building blocks of the nascent software package. Either simultaneously or directly following implementation is testing, which is the process of finding bugs and rooting them out systematically so only clean code goes into the package.

Every step taken by the software developers must be documented and documentation is a step in its own right in the SDLC. A record of exactly what was done, how and when is critically important for the future improvement of the software and refining that may be needed at a later stage. The documentation step may also involve writing the Application Programming Interface (API).

Deployment follows and is the stage where the software is approved for release and goes live for the first time. Usually, there will be fixes, patches and refinements that the client requires, or bugs may pop up unexpectedly as the software encounters real-life use for the first time.

Maintenance naturally follows and involves implementing the various refinements that are necessary, taking change requests from the client and carrying them out, weeding out errors and bugs, and generally improving the performance of the software package. The uninitiated might think this stage will not be necessary, but truth be told, it can take longer than the initial development.

The SDLC above presents a rather simplistic overview of what is an extremely complex process that can be carried out according to different models. Each stage can be completed before the next one begins, there can be a greater emphasis on testing with procedures written into the scope document, or a working version can be produced early on with an ongoing process of refinements.

While the SDLC remains constant, the models followed can differ widely and depend on several factors, including internal processes, client preference, the characteristics of the software package under development, and the budget available at each stage.

The most important consideration before launching into the development of a bespoke software package is to remember that the process is complex and takes time. While the goal is to deliver the package on time and on budget, reason should prevail as rushing a software project is never a good idea. Having a clear understanding of the process and the time frames as explained in the scope document will assist in managing expectations and facilitating a smoother development process.