A Selection-Criteria Algorithm
There's no perfect answer to a question like yours, since every organization is different. However, there are certainly some basic process patterns for defining criteria within a given context.
One such pattern is:
- Define your stakeholders.
- Identify your stakeholders' goals for whatever tool you're selecting. This will define value.
- Identify how you plan to measure the success or failure of the tool to deliver this value. This will define your selection criteria.
- Build an assessment plan to rank or filter your options based on those measurable dimensions.
- Research or brainstorm your options.
- Calculate the best available option from the field of candidate solutions.
Whether your value metrics and selection criteria are pass/fail or quantitative is really up to your team. It's always good to review your selection process with the entire team to make sure everyone's on board with your methodology.
Calculations Will Vary
Calculating ROI is highly situation-dependent, because gains, costs, and periods are up to you to define. The basic calculation for a given period is:
ROI for period = gain / cost
Selecting by ROI is straightforward:
- Calculate your ROI for each candidate solution.
- Rank each solution by the monetary value of its ROI.
There are also other ways to assess potential value, and you can make them as simple or as complex as you like. For example:
- Selecting the tool that meets the most criteria, reducing the problem to summing a set of check-boxes.
- Using a composite score based on a relative costs and benefits for each distinct criterion. A good example of this would be relative weighting.
It really doesn't matter what calculation method you use, though, as long as you have buy-in from all the stakeholders. The important thing is that everyone agrees on an approach, and that afterwards everyone can see how the final decision was made.