For a qualitative analysis of a strategic decision you might use a Lickert-type scale via surveys. For a quantitative analysis you might choose to examine some type of return on investment (ROI). What are the units of the strategic decision?
Qualitative analysis of strategic decision could be done by surveying the opinions of the stakeholders on parameters like : Qualitative benefits to the stake holders , Acceptability by the stake holders, Ease of implementation , change in the level of satisfaction / dissatisfaction of the stake holders , sustainability etc.
Quantitative analysis could be on the basis of factors like tangible benefits ( in revenue growth, income growth, market share etc), cost of implementation etc.
In both the cases, relative weights can be given to each factor and overall weighed average may be worked out.
Are you interested in measuring a perceptive grade of "quality" or associate the decision to other variables as suggested from Jeremy Robertsen. Under this perspective think about the objectives he/she may have to accomplish or which are the expectations from the share or stakeholder of the firm/organization. I think there is no "absolute" quality but the ones that are relatively important for the organization or industry. For instance, an ethical behaviour could be considered qualitative indicator.
Hi. Please pay attention very carefully. The best method for evaluation and measurement of the quality of the Strategic Decision is the Shannon's Entropy. This method is very perfect and practical method for your purpose. Good luck.
Quality of strategic decisions reflect in their outcomes. if the outcome is effective then quality of the decision is also good e.g. if certain strategic initiatives are taken to reduce employee turnover (which is affecting the organisational image as well as performance) then the quality of those initiatives will reflect in reduced employee turnover.
Irrespective of whether the decision is strategic or not, effectiveness can be measured across four dimensions, viz., quality, speed, yield, and effort. Of course, high-performance organizations make high-quality decisions: but, they also arrive at them faster than their competitors; they translate them into action more effectively; and, they devote appropriate amounts of effort to the processes that underpin each.
The quality of strategic decisions can be measured by using PMM systems such as Balanced Scorecard. This includes lead and lag variables of performance. You may also see papers on Flexible Strategy Game-card, which takes the duality of Enterprise strategic factors and Customer factors.