This document defines "deficiency" under the Consumer Protection Act of 1986 as any fault, imperfection, shortcoming or inadequacy in the quality, nature, or manner of performing a service that is either required by law or undertaken as part of a contract or otherwise. It notes deficiencies can arise from services rendered with faults, imperfections, shortcomings or inadequacies in terms of quality, nature or performance. The definition excludes free services or contracts for personal service. Examples of potential deficiencies in airways and banking services are provided.