1. A seminar report on:
Computer Aided Process
Planning
Submitted by:
Abinash Jena
Birla Institute of Technology,
Mesra

2. INTRODUCTION
 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 in that it provides
for the planning of the process to be used in producing a
designed part.
 Process planning is a production organization activity that
transforms a product design into a set of instruction
(sequence, machine tool setup etc.) to manufacture
machined part economically and competitively.
 CAPP is the method of automatically generating the
sequence of manufacturing operations

3. Initial Form Final Form
CAPP is a direct
connection between
design and
manufacturing

4. Characteristics
 CAPP capable of understanding and analyzing the part
characteristics.
 It possess knowledge about machine tools, cutting tools,
etc..
 It possess the capabilities of analyzing the
interdependencies between part, machining process,
quality, cost.
 It possess multiple calculating capabilities

5. Types of approaches:
Variant process planning
Generative process planning

6. Variant process planning
The variant process planning approach can be
realized as a four step process
 Definition of coding scheme
 Grouping parts into part families (Group Technology)
 Development of a standard process plan
 Retrieval and modification of standard process plan

7. Part coding &
classification
Formation of
Part family
Preparation of
Standard plan
Part family
search
Standard M/c
Route retrieval
Standard
Operation retrieval
And edit
Process plan
editor
Final
process
plan
Operations sequence file
Part family matrix file
Machine routing file
Other applications file
Preparatory stage
Production stage
Diagram of Variant process plan:

8. Generative process planning:
 It is the system which creates plan by means of
decision logic, formulas, geometry based data and
other logical procedures.
 In this method process plans are prepared without
the assistance of human and predefined plans
 After retrieving this information, the system can
generate the required processes and process
sequences for the work part.

9. Two major components of generative
 Geometry description and coding component:
 This defines all geometric features for process related surfaces
together with feature dimensions, locations, tolerances and the
surface finish desired on the features.
 The level of detail is much greater in a generative system than a
variant system.
 Process knowledge database & decision making logic:
 The knowledge will be in the form of decision logic.
 It is required to match the part geometry requirement with
manufacturing capability using decision logic and data.
 It includes selection of processes, mfg. equipments, work holding
devices, jigs & fixtures, inspection instruments, etc.

10. Geometric definition
From CAD
Part interrogation
Feature extraction
Feature recognition
Selection of
process
Selection of
M/C tool
Operations and
Time calculations
Interferencesystem
M/C specification
& capability
Knowledge
Acquisition
Knowledge
Base
Final
Process
Plan
Diagram of Generative process Plan:

11. Benefits of CAPP:
Productivity
Consistency
of plans
Accuracy of
plans
Capacity
utilization
Ability to
Introduce New
technology
Increases
Lead time of
Process plan
Routine clerical
work
Mfg. and process
Planning cost
Work in progress
Skill requirement
Of planner
Reduces