I’ll take a stab at this. For similar projects, or variations of similar projects where you need to select an optimal strategy for a specific project, I’d have a multi preference objective model which would be a customized project template with key performance parameters in columns and the rows would help specify specific design options. E.g. a column could be “vehicle range” with values 1-5 (1 = 100 miles, 2 – 200 miles, ….). Dont get carried away with too many key parameters for a project. The rows would specify various implementation scenarios for this project (less range & less weight & cheaper tires; greater range & greater weight & more expensive tires). Then for that project you would have to evaluate your optimal decision. This presents a level of fairness with your team in evaluating various decisions. This needs to get linked back to your strategy so you do not get carried away. (I wrote some VBA to generate readable reports of the spreadsheet info).
Ok, that kinda works for a project, but you will have a bunch of projects, so, presumably these need to be linked to a strategy. What good is implementing a project perfectly if it is not in line with your strategy. So, it would be really good to clearly articulate your strategy and to review this over time.
So, it seems you need something at a higher level which defines your strategy of your organization and this should help drive you toward the general projects you need to consider. You need to consider project risks, the risk of inactivity, etc. I’m out of date on this stuff, but check out Project Management Institutes books on portfolio management and strategy alignment. You want to consider the risks associated with highly technical projects, projects that need to be rolled out at many locations (because mistakes are expensive to correct).
I somewhat followed Markowitz efficient frontier portfolio management (very notionally) with my results and felt I had something to explain in my organization. Simple is better, its easy to get overwhelmed with spreadsheets and charts. Bubble charts helped differentiate the various projects.