At ISS we are firm believers in employing an Agile solutions methodology. Agile methods emphasize realtime communication, preferably face-to-face, over written documents. Most agile teams include all the people necessary to finish software. At a minimum, this includes installers/developers and our customers (customers are the people who define the product; they may be product managers, business analysts, or actual customers).
An Agile method also emphasizes a working solution as the primary measure of progress. Combined with the preference for face-to-face communication, agile methods produce very little written documentation prior to implementation relative to other methods.
Requirements Analysis Extracting the requirements of a desired solution is the first task in creating it. While customers probably believe they know what the solution is to do, it may require skill and experience in solutions engineering to recognize incomplete, ambiguous or contradictory requirements.
Development/Installation If custom components are required, this stage of the lifecycle involves the creation of those custom components. And it may or may not be the largest portion of the lifecycle.
Testing is the process of ensuring that end user requirements have been met.
Documentation An important (and often overlooked) task is documenting the internal design of a solution for the purpose of future maintenance and enhancement.
Software Training and Support A large percentage of software projects fail because the developers fail to realize that it doesn't matter how much time and planning a development team puts into creating software if nobody in an organization ends up using it. People are occasionally resistant to change and avoid venturing into an unfamiliar area, so as a part of the deployment phase, its very important to have training classes for the most enthusiastic software users (build excitement and confidence).
At ISS we pride ourselves on successfully combining all aspects of the lifecyle to bring our customers fully implemented solutions.