Computer Aided process planning

Manufacturers have been following an evolutionary step to improve and computerize process planning in the following five stages:

Stage I: Manual classification; standardized process plans

Stage II: Computer maintained process plans

Stage III: Variant CAPP

Stage IV: Generative CAPP

Stage V: Dynamic, generative CAPP

Earlier to CAPP, producers attempted to triumph over the issues of manual process planning by basic categorization of parts into families and developing standardized process plans for parts families that is called  Stage I.

When a new part is initiated, the process plan for that family would be manually recovered, marked-up and retyped. While this improved output but it did not enhance the quality of the planning of processes.

Computer-aided process planning originally developed as a device to electronically store a process plan once it was shaped, recover it, amend it for a new part and print the plan. It is called
Stage II. Other ability of this stage is table-driven cost and standard estimating systems.
Stage III: Computer-aided approach of variant CAPP is based on a Group Technology coding and classification approach to recognize huge number of part attributes or parameters. These attributes permit the system to choose a baseline process plan for the part family and achieve about ninety percent of the planning work. The schemer will add the remaining ten percent of the effort modifying or fine-tuning the process plan. The baseline process plans stored in the computer are manually entered using a super planner concept that is, developing standardized plans based on the accumulated experience and knowledge of multiple planners and manufacturing engineers.

Stage IV: It is generative CAPP. In this stage, process planning decision rules are developed into the system. These decision rules will work based on a part’s group technology or features technology coding to produce a process plan that will require minimal manual interaction and modification.

While CAPP systems move towards being generative, a pure generative system that can create a complete process plan from part classification and other design data is a goal of the future. These types of generative system will utilize artificial intelligence type capabilities to produce process plans as well as be fully integrated in a CIM environment. An additional step in this stage is dynamic, generative CAPP which would consider plant and machine capacities, tooling availability, work center and equipment loads, and equipment status in developing process plans.

The process plan developed with a CAPP system at Stage V would differ in due course depending on the resources and workload in the factory. Dynamic, generative CAPP also entails the need for online display of the process plan on a work order oriented basis to cover that the appropriate process plan was provided to the floor.

There are numerous advantages of this type of process planning. It can decrease the skill required of a planner. It can reduce the process planning time. It can reduce both process planning and manufacturing cost. It can create more consistent plans. It can produce more accurate plans. It can increase productivity. Automated process planning is done for shortening the lead-time, manufacturability feedback, lowering the production cost and consistent process plans. Advantages of Computer-aided Process Planning include reduced demand on the skilled planner, reduced process planning time, reduced process planning and manufacturing cost, created more consistent plans, produced accurate plans, increased productivity, increased high flexibility, attained high efficiency, attained adequate high product quality and possibility of integration with the other automated functions and systems.

Manufacturing Process Planning delivers essential process planning potential for all manufacturing industries. Using Manufacturing Process Planning, process planners can powerfully create and authenticate the original process plan using the product structure from product engineering, modify the plan to specific requirements, and link products and resources to the steps of the plan.

To summarize, Process Planning is important action in a production enterprise that verifies which processes, materials, and instructions will be used to produce a product. Process planning describes a manufacturing facility, processes and parameters which are to be used to change materials from a primary form to a predetermined final stage.