Risk is a measure of future uncertainties in achieving program performance goals and objectives within defined cost, schedule and performance constraints.
Risk can be associated with all aspects of a program (e.g., threat, technology maturity, supplier capability, design maturation, performance against plan,) as these aspects relate across the Work Breakdown Structure (WBS) and Integrated Master Schedule (IMS). Risk addresses the potential variation in the planned approach and its expected outcome. While such variation could include positive as well as negative effects, this guide will only address negative future effects since programs have typically experienced difficulty in this area during the acquisition process. 
- Risks that are safety related are managed in accordance with MIL-STD-882D
AcqLinks and References: