The feasibility study is not the initial project step. The first step involves gathering requirements. This is perhaps the best time to examine the project’s viability and potential ROI. A common part of this procedure is to list the assumptions of the business analysts, particularly if they are consultants. However, even company managers make assumptions about personnel and project potential. It is good to list these assumptions as they will often “flavor” the analysis results.
Together, the assumptions and requirements create mental model of the business. First, the consultants must make a few assumptions and operate on them until they gather enough facts to prove the assumptions true or false. Assumptions are important, but they could depend on the consultant's past experience in similar situations. Therefore the assumptions must be defined and must be available for evaluation and change while gathering requirements.
A Requirements Gathering Report that includes assumptions is available for you to download.