Business case v.s. Feasibility study

This is an interesting one, feasibility CANNOT and SHOULD NOT come before the business case (need). Think of it this way, there is a business requirement (regulatory, cost or time-saving initiative or just plain modernizing how we do things) that must be fulfilled. We now look at different ways to accomplish the business requirements, once we have listed choices, we narrow down using whatever criteria that is feasibility.

Using costs, longevity, support and availability are various factors used to see if a project is feasible or not.

Business Case and Feasibility Study are two different tools with different purposes.

Business Cases inform the decision to initiate a project, if there is a good amount of uncertainty before that, one or more feasibility studies can reduce the uncertainty, technically and commercially. I have seen many (most) business cases without a previous feasibility study.

Feasibility studies take a deep dive into a solution scenario and reduce uncertainties. This can be useful within a project. The effort and time of such a study should be balanced with the expected benefit. Reducing uncertainty does not mean being 100% sure.

It really depends on your gating process. You may need to do a business case to get the funding for the feasibility study.

The result of the feasibility study may lead you into a new business case to invest in a particular solution.

This is an interesting one, feasibility CANNOT and SHOULD NOT come before the business case (need). Think of it this way, there is a business requirement (regulatory, cost or time-saving initiative or just plain modernizing how we do things) that must be fulfilled. We now look at different ways to accomplish the business requirements, once we have listed choices, we narrow down using whatever criteria that is feasibility.

Using costs, longevity, support and availability are various factors used to see if a project is feasible or not.

I notice there are options for feasibility before and after. Maybe let us define what a business case is intended to achieve first. When you submit a business case you do so in order for a choice to be made to support an option i.e. let use a generic example of getting a loan for a new shop. When you submit your business case the bank does not say OK here is the money now go out and see if this is even feasible. Do they?

So it stands to reason that whatever option/s you present in your business case must be backed by feasibility hence a feasibility study is done before you write and submit your business case.

Looking at a project - How do you come to some sort of a conclusion if whatever solution your business case is proposing is even possible? Do we not perform analysis (such as SWOT) to determine if the solution we are asking money for (the reason for a business case) can actually be implemented should the case be approved? How inefficient would it be to submit something, get approval, find out if it can be done, no it can't, subnit new proposal, get approavl, find out if it can be done.........

The business case should be created first for addressing the opportunity to be pursued or risk to mitigate. Then, the feasibility study that explores other parameters like finance, resources, time, regulations, etc.
But, depending on organisations, both documents can be combined into one or overlap...