Think about the impact on workforce and partnerships as well as communities, both now and in the longer term. Often the value of services is multiplied by assessing the ‘ripple effects’ on people who are not the obvious beneficiaries, like families. Also looking for things that might affect the future planning and processes will help when valuing preventative services.
Social Return On Investment analysis is a good way to capture broader benefits for services and Local Money Multiplier (LM3) does a similar job in neighbourhoods. They are complex approaches, but borrowing elements from the methodology can be a good starting point when the resources aren’t there for more evaluation.
You should also find a way to capture organisation learning as well as unexpected or negative outcomes.