System development lifecycles & requirements

One topic that I have not seen examined, is how using a different System Development Life Cycle (SDLC) methodology affects a Business Analyst's requirement gathering approach. There are many different methodologies that are used on projects. Some of the different SDLC models include:

• Waterfall
• Spiral
• Extreme Programming (XP)
• Scrum
• Crystal
• RUP

If you view SDLC methodologies as a continuum, at one end of the spectrum you will find the waterfall model and at the other you will find the Agile approaches (the picture is based on some of the work done by a close friend.) As a Business Analyst it is very important to understand how your approach may change depending on the SDLC used. Of course, you must first speak with the project manager to clearly define and set expectations (as discussed in my previous posts: Set expectations & Time estimation.)

For a waterfall model you will want to get all of your requirements before you move to the next stage of the development life cycle (let's exclude change requests from this discussion.) Whereas when you are working on a project using an Agile methodology, you are providing discrete requirement sets based on their priority.

As a Business Analyst you must be flexible in your approach to conform to the SDLC that your project will use. When an Agile model is being employed, you must be willing and able to filter out everything that does not focus on the specific requirement set that has been chosen. For individuals that are used to a waterfall approach, letting go can be a difficult mental hurdle to cross.