This document is to be completed by Components Engineering and copied to Purchasing. This is a control document that includes the critical specifications, including dimensions, drawings, package styles, foot prints, and other parametric data that uniquely define the part of concern. This document may also be referred to as an SCD, or Specification Control Drawing. Many times Purchasing will be challenged by a stock shortage or outage situation and will quickly have to source an alternate part to keep the factory running. Typically, Purchasing personnel do not have the expertise to qualify a manufacturer’s suggested replacement part. The PSD document contains the critical form, fit, and functional information need to BEGIN the qualification process and subsequently the sourcing of an alternate part. The Purchasing department should have a file covering every active part used in a factory build. Documentation Control will have mechanical and assembly information on higher level components, but may not necessarily be maintaining part data as well. This is the job of the Components Engineer.