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