Production, Process and Operations Planning

Introduction 

As companies require implement computer-aided process planning along other manufacturing information systems, they shall do well to scrutinize the needs of all system users.

One of the most significant steps in modified a design concept into a manufactured product is procedure planning. The essence of that task is the formation of a complete package of information on how to carry out the manufacturing procedure, which may include work instructions for the shop floor, a quality control plan, a bill of material, tool planning, and so on. There may be also links to other manufacturing systems such like PDM (product data management), MRP (material requirements planning), engineering and manufacturing change control, time standards, shop floor control and data collection systems. In most of the cases, this initial package of information finally determines the final cost and quality of the product.

Traditionally, manufacturing engineers generated the necessary procedure planning documents from scratch by using manual techniques. That needed the retrieval and manipulation of a great deal of information from several sources including established standards, machinability data, tooling inventories, machine capabilities, stock availability and, expectantly, existing practice. The resulting procedure plan was then manifest in the form of printed text, lists and drawings.

Process planning translates design information into the procedure steps and instructions to effectively and efficiently manufacture products. As the design procedure is supported by several computer-aided tools, computer-aided process planning (CAPP) has evolved to simplify and develop process planning and attain more effective use of manufacturing resources.

Prior to CAPP, manufacturers attempted to overcome the difficulty of manual procedure planning by primary classification of parts into families and developing somewhat standardized procedure plans for parts families. While a new part was introduced, the procedure plan for that family would be manually marked-up, retrieved and retyped. While this developed productivity, it did not develop the quality of the planning of processes and this did not easily take into account the differences among parts in neither a family nor improvements in manufacture processes.

Computer-aided process planning primarily evolved as a means to electronically store a procedure plan once it was formed, retrieve it, change it for a new part and print the plan. Other capabilities of this stage are table-driven expense and standard estimating systems. This initial computer-aided approach evolved into what is now known as "variant" CAPP. Though, variant CAPP is depend on a Group Technology (GT) coding and classification approach to recognize a larger number of part parameters or attributes. These attributes permit the system to choose a baseline procedure plan for the part family and accomplish around ninety percent of the planning work. The planner shall add the remaining ten percent of the effort changing or fine-tuning the process plan. The baseline process plans hold in the computer are manually entered by using a super planner concept that is, producing standardized plans depend on the accumulated experience and knowledge of manufacturing engineers and multiple planners.

The next stage of evolution is toward generative CAPP. At this stage, procedure planning decision rules are made into the system. These decision rules shall operate depend on a part's group technology or features technology coding to generate a process plan that shall require minimal manual interaction and modification (for example entry of dimensions).

Objectives

After studying this unit, you should be able to

• Explain significance of computer aided process planning in computer integrated manufacturing,
• Describe production planning, process planning, and operation planning,
• Define production planning system, and
• Understand benefits of capp.