An end-to-end engineering process employs a linear workflow where a design is conceived and then realized. Design data held in computer space or a blueprint acts as the initial stage of prefabrication, with raw materials and capable high-end tooling taking on the role of the developmental stages required to fabricate mechanical parts. The process branches and adapts to introduce CAD automation and fabrication strategies that are goal-oriented, translating an accurate model or template into a finalized product constructed of technically specified materials.
Switching from this mode of fabrication to reverse engineering retains the workflow but changes the sequence. Instead of manufacturing the component from scratch, we jump to the end of the process, to a part that's already in service, and work backwards. The component is meticulously analyzed to create new data, distilling physical dimensions and material fabrication observations into a comprehensive series of spatial data. This data can be used by CAD software to reconstitute the part even if there is damage to the component. As long as all dimensions are available or can be accurately extrapolated, then the fabrication process is viable.
The technique of reverse engineering has been abused in the past, used to manufacture copies of competitor products, but the legitimate usage of the process is a million miles from this unsavory intention. Reverse engineering is crucial in replacing damaged components, in fabricating replacement parts when a digital model or technical blueprint no longer exists. Obsolete parts may have no intrinsic value to the modern world of engineering, but a third-world nation or a company getting along on ancient machinery relies on this analytical art, on the forensic skill involved in dissecting an object and condensing it into dimensional data.
The key to the process lays in accurate measurement. The part in question is measured on all three dimensions, but manual tools are unlikely to meet this task unless we're talking about a simple table without complex features such as curves and contours. Instead, advanced scanning equipment is typically used to extract dimensional data. The equipment combines lasers, structured light digitizing, and reflective scanning to create a detailed 3-D model of the component. From here the data can be converted into a familiar CAD language, and we return to a standard linear workflow. This is a key science in maintaining working systems, especially in systems where parts have worn or broken down. The state-of-the-art measurement tools construct the computer model, extrapolating the working shape of the part as originally designed. Material analysis provides the final part of the puzzle, the raw material for manufacturing the replacement part.
The development of specialized software solutions dedicated to the discipline of reverse engineering go further than designers ever imagined. New solutions include handheld scanning, the ability to plug in the model data to simulation packages and test the modeled part in 3-D space, perhaps improving the part, modifying it or fabricating the component from a different material before shifting the final design to the milling and machining stage.