The ________________ contain the step-by-step procedures to follow to create the final assembly.

Work instructions are essential documents that provide detailed, step-by-step procedures necessary for performing tasks associated with assembly. They ensure that assembly mechanics can accurately follow established methods to create the final product. Each work instruction outlines the specific processes, tools, and materials needed for various assembly stages, helping to maintain consistency and quality in production.

Other options, while related, do not serve the same purpose. Assembly guidelines generally offer broader instructions but lack the detailed, sequential steps that work instructions contain. Project plans outline the overall timeline and resources for a project rather than specific procedures for assembly. Engineering specifications detail the design and functional requirements of products but do not present the hands-on processes for assembly. Therefore, work instructions are the most appropriate choice for step-by-step assembly processes.