This paper presents a methodology to generate manufacturing routes and operations using rules of precedence to provide logical approach in their dimensioning and chaining. The rules of precedence order and prioritize the knowledge of various manufacturing processes, taking into account the theories of machining, forging, assembly, and heat treatments; also, utilizes the theories of accumulation of tolerance and process capability, between others. The proposed methodology requires development of manufacturing data bases of manufacturing process, tolerances and capabilities, deviations of the machine tool - cutting tool - fixture device and work piece. The rules of precedence make viable the generation of manufacturing routings and operations, through the usage of structured knowledge, instead of tacit one. This approach allows the structured development of manufacturing routes, which can be deployed to engineers working in the areas of manufacturing engineering.