Dear friends , i would like to through light on the subject of sigma level calculations at orgnization or unit level. Please follow the following steps. 1. Identify the Business CTQs. i take example of a manufacturing unit. The four critical Business CTQs are Productivity, Cost, Quality and Customer complaints. 2. Decide KPIs for these KRAs and UoM . Like Productivity - Ton per day or Kg /hour etc ( Treat variable data) Cost - Rs / ton or Rs /Kg (treat variable data) Quality - Defective ubits vs total units produced in the period for which sigma level is being calculated (treat attribute data) Customer complaint - Total units supplied vs unist with complaints Use the scroll up sigma level template to calculate combined sigma level of all 04 parameters to get the UNIT level sigma level. This can be done on monthly , quarterly or yearlly basis or for any period. I do not see any problem with changing specifications bcos it will be taken care by defect defintions iself. If you need any more inputs on this topic then feel free to contact me here. I have enough experience to deal with sigma level calculations and i think i can try to calculate sigma level of any function, unit, organization. Regards sanjay MBB-Mumbai