SSAS/SSRS : Building different gauges with MDX.

For one of my customers i've to build a dashboard. This customer wants to improve the quality of service. There are discussions about how do you measure quality, what is good service and what is bad service. The problem is that there are many departments and how do you compare them. Is it recommended to say below 50 is ok and above is not ok? So what is good and what is wrong? Just showing the number is also a bad practice (without any reference).