Steps in Process Planning
The various steps in process planning are:
- Analysis of the Product Print and Specifications
In this step, the process planning takes as input the drawings and other specifications which indicates what is to be made, and also the forecast orders in hand or contracts which mentions how many are to be made. The quantity of the product to be manufactured is usually given in the product specification; otherwise it can be attained from the sales department or the management. The process engineer should make a mental or written list of every item in the specifications to obtain a full grasp of the project.
- Improvement of the Specifications
Product specifications must be clear and explicit. If the specifications are faulty like overlapping dimensions, missing tolerances, etc. they are rectified by the process engineer in consultation with the production engineer.
The product might consist of number of parts or components. The process planning determines what parts are to be manufactured in the factory itself and what parts are to be purchased from the outside suppliers.
- Selection of Basic Manufacturing Process
Once the decision is taken about what parts are to be manufactured in house, the next step is, to prepare a list of basic operations needed to produce each component of the product. The operations listed are examined to find the practical methods by which the product can be manufactured. The several alternative methods are compared and the most practical and economical method is selected by calculating and comparing the total costs for two or more feasible processes.
- Determine the Sequence of Operations
Once the best manufacturing process is selected, the sequence of operations to be performed on each component is determined.
Generally, as many basic operations should be combined as are practical and economical.
- Prepare the List of Raw Materials
The raw materials needed to manufacture all of the components of the products are determined, considering the quantity to be produced.
- Selection of the Machine Tools or Equipments
The selection of the correct equipment or machine tool is intimately related to the selected process of manufacture. The factors that are frequently considered while selecting correct equipment are shape and size of the work piece, the work material, the accuracy and surface finish needed and quantity required.
Determination of the stages of inspection and also the need of designining inspection devices and restrict gauges to be utilized at different stages of manufacturing.
Estimating the type of labour required to do the job. This information is depend on the personnel department of the organisation for recruitment and selection.
Determination of the time standards for performance of the job, and fixing the rates of payment.
Assessment of the cost of production before the manufacturing starts.
- Prepare the Operation Sheet and the Route Sheet
The operation sheet illustrate everything regarding the operation, i.e., description of operations, their sequence, tools and equipment used, type of machinery, set up and operation times, feeds depth of cut, speeds etc.