Fit for purpose is a term that is becoming more important to business analysts.
COTS and SAAS software are becoming more prevalent.
When you can purchase a pre-existing solution, understanding the fit for purpose becomes more important.
Custom software can be modified. Customization in a COTS or SAAS is not recommended. Customization may not be supported as the product is updated.
Understanding the fit for purpose requires that the business analyst understands the business outcomes that need to be achieved. Clarity in the business outcomes will also highlight potential challenges in the gap between where the business is and the new solution.
It is a significant amount of work to determine the fit for purpose of a COTS or SAAS product. Without doing this work, business may adopt a solution that does not fit their needs.