Without standards, you get fragmentation. Fragmentation is a kind of friction. It isolates organizations, and parts of organizations, from each other. It forces people to negotiate unnecessary boundaries. It makes it less easy for people to work together. It stifles innovation. And it erodes quality.
Fragmentation also makes organizations – and entire industries – vulnerable to competition from more coherent rivals. Your competitors don't have to waste time and money on the institutionalized workarounds that compensate for fragmentation. Also, they are connected by default in their constituent elements, their partnerships, and their market access. Fragmented organizations can't even sense the opportunities they are missing – without the cognitive architecture that standards bring, they don't even know their worldview is incomplete.
The value of standards is potentially infinite, so it's debatable whether you should measure it. Measures of standards are important today because we still need to wake people to what they're missing. They need a ballpark for standards value, and that ballpark proves to be billions of dollars.
I believe we're now moving in to a phase where it's more relevant to measure the cost of fragmentation. Decision makers must attack fragmentation, rather than defending standards. We need people to make business cases for the fragmented status quo if they want to keep things that way.
It may actually be easier to measure the cost of fragmentation than the value of standards. Fragmentation is part of the as-is situation. There's lots of data points you can capture. What time does it take to progress this case from open to close? How many instances of rework are there for each type of case? How many local protocols are there for handling common data? How many spreadsheets get passed around?