We love information economics. It was one of the fist models that really excite dus becuase it gave a pretty definitive way to define the "benefits" of IT projects. It's use though is not limited to IT, and it can be used to evaluate almost any business system or proposal.
Essentially IE identifies a hierarchy of where "benefit" can come from. At the highest level are Tangibles, Intangibles, Risk and Enhanced ROI (or synergys). Tangibles are about money - costs and revenues. Nothing woolly is allowed like "saves time", saving time is only a benefit if it lets you save costs, earn more, or reduces risk. Within cost and revenue specific are identified like delaying or avoiding cost, and accelerating or protecting revenue.
Intangibles cover things like competitive responsiveness, or manageemnt information. Risk should be analysed with a conventional likelihood/impact model. Finally Enhanced ROI brings in more adavnced concepts such as value linking and value restructuring. Purists should probably use scenario modelling to drive these three down again to cost/revenue/risk elements.
Ultimately IE gives you a monetary value for a project. This could then be compared across several projects using an NPV/IRR type method.
Of course we realise that not everything comes down to money, but for business ultimately that is what it is about - if you cast the net wide enough to include stakeholders, societal and environmental impacts - and IE can help you do that analysis.
We have a range of project evaluation models that can be used depending on the size and type of projects. IE is just our favourite.
