Process Planning and cost estimating

Process Planning

• Process planning involves determining the most appropriate manufacturing processes and the order in which they should be performed to produce a given part or product so that it fulfills all the specification given by design engineering at a competitive cost.

• Process planning can be briefly defined as the function of scientifically and systematically determining the best possible methods laying down an efficient sequence of operations , selecting proper tools and equipment and take make or buy decisions, so that the end product can be manufactured efficiently and economically , so that the end product can be manufactured efficiently and economically ,yet conforming to the specifications laid in the product design.

Process planning requirement

To plan the manufacturing process for a designed product, the following information are required :

1. Job description and its end use

2. Specifications of the product

3. Assembly and sub-assembly drawing of the product.

4. Working drawings, with manufacturing specifications of the parts.

5. Number of product required to be manufactured over a period of time.

6. Quality specification for the product and its parts.

7. Quantity and specification of spare parts needed for each product, both standard and non standard.

8. Available manpower, raw material

9. Data pertaining to conditions for setup time, handling time, use of cutting fluid

10. Specification, capacities and layout of existing machinery and equipment.

11. Specification of available tooling

12. Process parameter data

13. Standard time for each operation.

Procedure of process planning

STEPS of process planning:-

1.Faimlier to end user 2. To determine the required accuracy level and out put by analyzing the production specifications and standards3. To study the product specification and find out the quantity of products to be manufactured annually.4. To carefully study the part drawings , select feasible manufacturing , If any mistakes in drawing get them rectified it.5. To take decision to buy required quantities.6. To prepare a material list

7. Determine most appropriate and economical raw material8. Determine the sizes of blank required if process like forging, stamping, and pressing.9. Specify the proportions and gross weights of raw material if casing involved.10. Determine the most economical and efficient manufacturing process.11. Sequence of operation12. Decide the machine tool 13. Special Aids and Accessories14. Decide Stages of inspection ,methodology and equipment15. Loading and unloading16. Determine time standard for different operation and fix payment rate.17. Specify the type and number of labor needed for particular operation18. Estimate the cost of proposed product.

Process Planning sheet

• Process plan is a very comprehensive document which contains the complete concept about manufacturing a product.

• It is also known by operation sheet, operation planning sheet, Analysis sheet, Instruction sheet, Process sheet etc.

• This sheet is the outcome of the effort put in by process planners and it is used by many other sections and departments of the firm.

• The format of this sheet is not universal it may vary with

organization to organization.

Process planning sheet

Cost Estimating

• Cost Represents the expenditure incurred on an object.

• Cost estimating is the process of evaluating the expenditure in advance of the actual manufacture.

• In other words the process of making an advance assessment of the likely expenditure in manufacturing of a product .

• This assessment of cost takes in to account the entire expenditure like

Cost of design

manufacturing cost

Service related to the process

Why cost estimates are required ?

1. To determine the cost of manufacturing a product or a part.

2. To determine the cost of manufacturing the required jigs, tools ,dies etc

3. To determine the selling price of a product

4. Make or Buy decision

5. to select economical method

6. To find out the ways of cost reduction of a product

Elements of Cost

Capital cost: Non recurring cost , one time expenses only in the initial stage of establishment of the plant. Also known as fixed cost.

Material cost

Labor cost

Expenses

Expenses conti…

Structure of Cost1.Prime Cost: Also known as direct cost Prime cost = Direct material cost + Direct labour cost Direct expenses2.Factory cost : Also known as Works cost Factory cost = Prime cost + Factory expenses3. Manufacturing cost: Also known as production cost Manufacturing cost = Factory cost + Administrative expenses4. Total cost : Cost of product Total cost = Manufacturing cost +Selling and distribution expenses5.Selling price : Selling price = Total cost + profit

Cost structure of a product

Some useful costing terms

1. Fixed Cost: Tendency to remain constant even if the quantity of production or sales changes are called fixed costs. For eg: staff salaries, rent of building, administrative expenses, established Machinery cost etc

2. Variable cost: Tend to vary directly as the variation in the quantity of production are called variable cost. Eg: Direct material cost, direct labour cost, direct expenses etc.

3. Predetermined cost : Cost which is worked out before actual production and based on product specification.