The major insurance companies specify which materials and parts should be used in the repair of their policy holder’s car. Negotiations on price and volume discounts are conducted directly by insurers with paint manufacturers, OEMs and alternative parts suppliers. These market-based exchanges specify the prices that crash repair centres will be charged and therefore allow the insurer to control, in part, the costs of materials. For crash repair centers operating under a captive governance structure this mean that they cannot order any materials or commence any work before authorization from the insurance engineer. Crash repair centers under a modular approach can order material and commence work without authorization.