introduction to process planning

1. PROCESS PLANNING
Process planning is defined as conversion of design data to work
instruction
Process planning is defined as systematic determination of methods by
which a product is to be manufactured economically and competitively.
It consists of
 Devising (arrange),
 Selecting
 Specifying process
 machine tools
to convert raw material to finished products
Process planning is also called:
 manufacturing planning,
 material processing,
 machine routing.

2. PROCESS
PLAN
 Process plan is also called as
 operation sheet
 route sheet
 The detailed plan contains:
 Route (printed sheet)
 Processes (welding , drilling , milling , lathe operations, etc.,)
 process parameters
 machine and tool selections
 (lathe, shaping m/c & drill bit, single point tool etc.,)
 Fixtures (milling fixture , drilling fixture)
 Machining time
 Detail of how the plan is depends on the application.
 Operation Plan sequence & Summary of a process plan.

3. PROCESS
PLANNING
Design Machine
Tool
Scheduling and Production Control
Process
Planning

4. Concept of Process Planning
Product design
(specifications, requirements)
Process planning
Operation programming
(suitable process such as grinding , welding,
milling, heat treatment process)
Verification
(make buy decisions)
Scheduling
(Rout sheet)
Execution
Process,
machine
knowledge
Scheduling
knowledge

5. Detailed Process Plan

6. Process Planning Activities
Analyse (Part ,dimension requirements) [DRAWING INTERPRETATION]
Determine (operation sequence) [MATERIAL EVALUATION AND PROCESS SELECTION]
Select (equipment ) [SELECTION OF MACHINES . TOOLING and WORK HOLDING DEVICE]
Estimate (manufacturing cost) [COST ESTIMATING]
Calculate (processing times ) [SETTING PROCESS PARAMETERS]
Document (Process Plan ) [PREPARING PROCESS PLANNING DOCUMENTATION]
Communicate (manufacturing Engineer with shop floor)
Select (QA/Inspection methods) [SELECTING QUALITY ASSURANCE METHOD]

7. Dra
win
g
Inte
rpre
tati
on
(En
gin
eeri
ng
Dra
win
g)
• Aim and Objectives
Identify appropriate supplementary information from
the drawing to aid the process
Identify and interpret dimensional information from
the drawing
Identify and interpret geometric information from the
drawing
Identify the critical processing factors for the
component from the dimensional and geometric
information from the drawing

8. Dra
win
g
Inte
rpre
tati
on
• Types of Drawing
Detail drawing
I. Single part drawing
II. Collective drawing
Assembly drawing
I. Single assembly drawing
II. Collective assembly drawing
Combined drawing

9. Part drawing

10. FACTORS AFFECTING
PROCESS
PLAN SELECTION
• Shape
• Tolerance
• Surface finish
• Size
• Material type
• Quantity
• Value of the product
• Urgency
• Manufacturing system itself
• etc.

11. MATERIAL EVALUATION
• IMPORTANT FACTORS
Product design must meet the specified need
Materials with appropriate properties must be
selected
Suitable manufacturing process must be selected
The response of the material during manufacture and
its service

12. MATERIAL EVALUATION
AIM and OBJECTIVES
 Identify and specify common material used for
manufacture
 Identify and specify the main properties of the material
 Identify and specify the common material selection
process
 Identify and specify the common process used for
manufacture
 Carryout an overall evaluation of the selection of
materials for manufacture in terms of processes
 Select the suitable process for given product based on
critical processing factors identified during the drawing
interpretation

13. MATERIAL EVALUATION
Type of material

14. MATERIAL EVALUATION
material properties

15. MATERIAL EVALUATION
Types of metal

16. PROCESS PLANNING APPROACHES
 MANUAL
 COMPUTER-AIDED
 VARIANT (Retrieval)
 GT based
 Computer aids for editing
 Parameters selection
 GENERATIVE
 Some kind of decision logic
 Decision tree/table
 Artificial Intelligence
Objective-Oriented
Still experience based

17. REQUIREMENTS IN
MANUAL PROCESS
PLANNING• ability to interpret an engineering drawing.
• familiar with manufacturing processes and practice.
• familiar with tooling and fixtures.
• know what resources are available in the shop.
• know how to use reference books, such as machinability
data handbook.
• able to do computations on machining time and cost.
• familiar with the raw materials.
• know the relative costs of processes, tooling, and raw
materials.

18. MANUAL PROCESS PLANNING STEPS
• Study the overall shape of the part. Use this information to
classify the part and determine the type of workstation
needed.
• Thoroughly study the drawing. Try to identify every
manufacturing features and notes.
• If raw stock is not given, determine the best raw material
shape to use.
• Identify datum surfaces. Use information on datum
surfaces to determine the setups.
• Select machines for each setup.
• For each setup determine the rough sequence of
operations necessary to create all the features.

19. MANUAL PROCESS PLANNING STEPS
• Sequence the operations determined in the previous
step.
• Select tools for each operation. Try to use the same
tool for several operations if it is possible. Keep in mind
the trade off on tool change time and estimated
machining time.
• 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.

20. COMPUTER-AIDED
PROCESS
PLANNING
ADVANTAGES
1. It can reduce the skill required of a planner.
2. It can reduce the process planning time.
3. It can reduce both process planning and manufacturing
cost.
4. It can create more consistent plans.
5. It can produce more accurate plans.
6. It can increase productivity.

21. Variant Process Planning

22. PROCESS
PLANNING
Machining featuresDesign
Workpiece Selection
Process Selection
Tool Selection
Feed, Speed Selection
Operation Sequencing
Setup Planning
Fixturing Planning
Part Programming

23. PROBLEMS ASSOCIATED WITH
THE VARIANT APPROACH
1. The components to be planned are limited to similar
components previously planned.
2. Experienced process planners are still required to modify
the standard plan for the specific component.
3. Details of the plan cannot be generated.
4. Variant planning cannot be used in an entirely automated
manufacturing system, without additional process
planning.

24. ADVANTAGES OF THE
VARIANT APPROACH
1. Once a standard plan has been written, a variety of
components can be planned.
2. Comparatively simple programming and installation
(compared with generative systems) is required to
implement a planning system.
3. The system is understandable, and the planner has
control of the final plan.
4. It is easy to learn, and easy to use.

25. GENERATIVE APPROACH
(i) part description
(ii) manufacturing databases
(iii) decision making logic and algorithms
A system which automatically synthesizes a process
plan for a new component.
MAJOR COMPONENTS:

26. ADVANTAGES OF THE
GENERATIVE APPROACH
1. Generate consistent process plans rapidly;
2. New components can be planned as easily as
existing components;
3. It has potential for integrating with an automated
manufacturing facility to provide detailed control
information.