An IBR is a formal review conducted by your customer. If your customer is the government, then they will conduct the IBR. If your customer is a prime contractor to the government and you are a sub tier contractor then the prime contractor will conduct the IBR. In either case, the Defense Contract Management Agency will be invited. The IBR is usually held at the contractor’s site and typically lasts from 2 to 5 days.
Typically the IBR should be held within 6 months of contract award. This is early enough in the program life cycle to be able to make any changes in the program baseline without significantly affecting cost schedule or scope.
The primary purpose of the IBR is to review the contract Performance Measurement Baseline (PMB) as awarded for cost, schedule and scope. This is usually the first and only time all members of the customer and your team are able to sit down together and discuss the "as" negotiated contract scope of work, schedule and associated costs.
An IBR is a formal review conducted by the customer program manager and technical staff, jointly with their contractor counterparts, following contract award, to verify the technical content of the performance measurement baseline, and the accuracy of the related resource (budgets) and schedules. An IBR will also be performed when work on a production option of a development contract begins or, at the discretion of the program manager, when a major modification to an existing contract significantly changes the existing PMB. When major events occur within the life of a program, e.g. PDR, CDR, etc., and a significant shift in the content and/or time-phasing of the PMB occurs, the Program Manager may conduct a review of those areas affected by the change with the associated resources and schedules. The intent is for the IBR to be a continuous part of the process of program management by both the customer and the contractor.