Outsourced mainframe customers often lack a clear understanding of how well their outsourcer is managing the mainframe capacity and performance relative to what is optimal for the customer. The customer seldom has access to the data needed to really understand their capacity usage and often lack the skills to communicate clearly with the outsourcer on capacity and performance questions. The outsourcer may have limited motivation to help the customer optimize capacity costs. In many cases, the customer doesn’t even have the ability to validate whether the outsourcer is invoicing in a correct manner relative to the contract or in a fair manner relative to industry ‘best practice’. Simple questions like ‘how is the basis for invoicing (e.g. MIPS) calculated?’ can lead to a 10% difference in the invoice.