This document summarizes computer aided process planning. It discusses that process planning converts design information into manufacturing instructions to effectively produce products. It then describes different approaches to computer aided process planning including manual process planning, variant approach using group technology and part coding, and generative approach. The variant approach retrieves standard plans while the generative approach automatically generates new plans by matching part geometry to manufacturing capabilities. Overall, computer aided process planning aims to reduce time, labor, costs and improve precision and understanding of manufacturing processes.

1. Computer aided process planning
Submitted to- Amit Pancharya
(Associate Professor, MNIT)
Submitted by- Maheshvar Nath Trivedi
(2019PPE5070)
Rajendra Prasad
(2019PPE5002)

2. Introduction
• A process is described as a set of steps that result in specific
outcome.
– It converts input into output.
• Process Planning is a complete description of specific stages
in the production process.
• Process planning converts design information into the
process steps and instructions to powerfully and effectively
manufacture products.
• All the specifications and conditions of operations are included
in the process plan.
• Process planning influences time to market and productions
cost

3. • Process Planning includes :-
– Manufacturing Planning
– Material Processing
– Process engineering
– Machine Routing
• It is a base /input for:-
– Designing factory building
– Facility layout
– Selecting Production equipments

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5. Objective of Process Planning
• Process planning is planned to renovate design
specification into manufacturing instructions and to
make products within the function and quality
specification at the least possible costs.
• Cost Reduction
– Fewer staff to complete the same process.
• Higher Competence
– By removing loops and bottlenecks.
• Greater Precision
– By including checkpoints and success measures to make sure process steps are
completed precisely.
• Better Understanding
– All employees to fulfil their department objectives.

6. Objective of Process Planning
• Process planning is planned to renovate design
specification into manufacturing instructions and to
make products within the function and quality
specification at the least possible costs.
• Cost Reduction
– Fewer staff to complete the same process.
• Higher Competence
– By removing loops and bottlenecks.
• Greater Precision
– By including checkpoints and success measures to make sure process steps are
completed precisely.
• Better Understanding
– All employees to fulfil their department objectives.

7. Process Planning Activities
Analyze(Part ,Dimension requirement) –Drawing
Interpretation
Determine(Operation sequence)- Material Evaluation
and Process Plan
Select(Equipment)- Selection of tooling , machines and
work holding devices
Calculate(Processing Time) –Setting Process parameters
– feed rate ,spindle speed.
Select(QA/Inspection Method)-Selecting Quality
Assurance method

8. Estimate(Manufacturing cost) –Cost Estimate
Document(Process Plan)
Communicate(Manufacturing engineer with shop
floor)

9. • Drawing Interpretation
– The Part and Product design must be analyzed .
• Starting material
• Dimensions
• Tolerances
• Process Sequences
– Describe all processing steps used to produce the work
unit.
– The order or sequence in which they will be performed.

10. • Equipment Selection
– The process planner tries to develop process plans
that utilizes existing plant equipment.
– Otherwise part must be purchased or new
equipment must be installed
• Methods analysis
– Hand and body motions, workplace layout, small
tools, hoists for lifting heavy parts
– Methods must be specified for manual operations
(e.g., assembly) and manual portions of machine
cycles (e.g., loading and unloading a production
machine).
• Work standards
– Time standards set by work measurement
techniques.

11. PROCESS PLANNING APPROACHES
1. Manual Process Plan
2. Computer Aided Process Plan
– Variant (Retrieval) Approach
– Generative Approach

12. 1. MANUAL PROCESS PLAN
• Manual process planning is based on a manufacturing
engineer’s experience and knowledge of production facilities,
equipment, their capabilities, processes, and tooling.
• It is very time-consuming and the results vary based on the
person doing the planning.

13. Steps
• Study the overall shape of the part.
• Thoroughly study the drawing.
• If raw stock is not given, determine the best raw material
shape to use.
• Select machines for each setup.
• Sequence the operations determined.
• Select tools for each operation .
• Select or design fixtures for each setup.
• Evaluate the plan generate thus far and make necessary
modifications.
• Select cutting parameters for each operation.
• Prepare the final process plan document.

14. Result/outcome
• Routing sheet which specify operations, operation sequences,
work centres, standards, tooling and fixtures.

15. COMPUTER AIDED PROCESS
PLANNING
• Computer-aided process planning (CAPP) is the use of
computer technology to aid in the process planning of a part or
product, in manufacturing.
• CAPP is the link between CAD and CAM
• It is capable of analyzing and understanding the part
characteristics.
• It possess the capabilities of analyzing the inter- dependencies
between part, machining process, quality and cost.

16. Various approaches to CAPP
Variant CAPP
• It is based on group technology and parts classification and
coding
• A standard process plan is stored in a computer files for each
part code number
• For each new part , an standard plan is identified, retrieved
and edited if modification are needed.
• Computer search for existing process plan.

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18. Group Technology
• Similar parts are being identified and grouped
together.
Implementing Group Technology
1. Identifying the part families:-
– Review all of the part drawings and grouping the parts into
families
2. Rearranging production machines into cells:-
– Rearrangement of machines into cells

19. Part Classification and Coding Method
• Two categories :-
1. Design attributes :- It is concerned with the part
characteristics such as geometry size and material.
2. Manufacturing attributes :- It is concerned with the
sequence of processing steps required to make a part

20. Three Basic Coding Structure
1. Mono code
2. Poly code
3. Mixed code

21. Three Basic Coding Structure
1. Mono code
2. Poly code
3. Mixed code

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24. Advantages:
• Reduction of time.
• Labor requirement.
• Reduced Development and hardware cost.
• Shorter development time.
Disadvantages
• Difficult to maintain consistency
• The quality of process plan depends on experience of process
planner

25. Generative CAPP
• Computer generates new process plan every time when a new plan
is needed.
• The process sequence is planned without human assistance and
without predefined standard plans.
• It is generated by decision logic, formulas ,technology algorithm etc.
Two Major components
• Geometry based coding scheme:- Define all geometric feature like
dimensions ,tolerances ,locations, desired surface finish.
• Process knowledge in the form of decision logic and data:-
Matching of part geometry to manufacturing capabilities using
process knowledge in the form of logic and data.

27. All steps are automatically carried out:-
• Like process selection ,machine tools ,tools ,jigs
fixtures ,materials ,inspection equipments and
sequencing of operations.
• Setup and machining time calculation.
• Operation instruction sheets.
• If the machines are numerically controlled, NC
codes are being generated automatically.

28. THANK YOU