What is the difference between a feasibility study, business case and business plan?

While both feasibility study and business case consider worth, viability, and options for a new business or government initiative, the focus of each document is different.

The feasibility study focus is to evaluate the technical and economic viability of a new initiative by establishing what criteria are to be met to attain the desired outcome and reasoning if and how the organization can meet these criteria, given its current vision, capabilities, and resources. Feasibility studies generally assume that the funds for the realization of the initiative are available.

The business case focus is to justify approval to proceed and the allocation of funds for the realization of the suggested new initiative. Business cases generally assume that the initiative is feasible and aim to build a funding submission based on conclusions of the preceding feasibility study.

The UK government's project authority provides a Functional Standard for projects. In this excellent document, they detail how a

(1) Project brief authorizes a feasibility study, resulting in a

(2) Strategic outline case, which goes through appraisal and results in a

(3) Outline business case; this moves through a definition stage where investment decisions are made and results in the

(4) Full business case; which by the way is updated as the project moves along.

The sequence is crucial for organizational governance

Feasibility Study are for new projects

Business case are unique and particular Job (case to case basis)

Business plan are done periodically for existing business for improvement and visualizing the future objectives.