1. Computer Integrated Manufacturing
Unit 1
By:- Mayur N Patel

2. CAD
“CAD can be defined as a use of computer systems to assist in the creation, modification, synthesis, and/or optimization of a design.”

3. CAM
CAM can be defined as a use of computer system to plan, manage, and control the manufacturing operation through the direct or indirect computer interface with manufacturing machine.

4. CIM
CIM is the complete integration and automation of all functions of factory. i.e. Design, manufacturing planning and control, manufacturing, and business functions.

5. Evolution of CIM It started developing as a technology since 1980.
With globalization of economy, the manufacturing industries all over the world started competing with each other.
Transformed the market from seller driven to customer driven.
This led to the emergence of the CIM

6. Prime factor for development in CIM
Development and advancement of CNC, FMS and automation technologies.
Development of cost-effective and high speed computer system.
Market challenges such as high labor cost, global competition, and buyer driven market.
Customer demands such as product variety, better quality and low cost product.

7. SCOPE of CIM
CIM applies computer and communication technology to completely integrate following four function.
Design
Manufacturing
Manufacturing planning and control
Business function

9. The two terms CAD/CAM and CIM are very closely related
The two terms CAD/CAM and CIM are very closely related. However, coverage of CIM is broader than that of CAD/CAM.
CIM includes all functions of factory operations which CAD/CAM covers in addition of it, also includes business functions of the factory.
The ideal CIM system applies the computer and networking technology to all the operational and information processing functions In manufacturing from order receipt, through design and production, to shipment of product.

10. Benefits of CIM Products quality improvement.
Shorter time in launching new product in the market.
Flow time minimized.
Inventory level reduced.
Competitiveness increases.
Improved scheduling performance.
Shorter vendor lead time.
Improved customer service.
Increase in flexibility and responsiveness.
Total cost minimized.
Long term profitability increases.
Customers lead time minimized.
Manufacturing productivity increases.
Work in process inventory decreases.

11. Classification of Manufacturing Systems
Factors that define and distinguish manufacturing systems:
Types of operations performed
Number of workstations
System layout
Automation and manning level
Part or product variety

12. Types of Operations Performed
Processing operations on work units versus assembly operations to combine individual parts into assembled entities
Type(s) of materials processed
Size and weight of work units
Part or product complexity
For assembled products, number of components per product
For individual parts, number of distinct operations to complete processing
Part geometry
For machined parts, rotational vs. non-rotational

13. Number of Workstations
Convenient measure of the size of the system
Let n = number of workstations
Individual workstations can be identified by subscript i, where i = 1, 2,...,n
Affects performance factors such as workload capacity, production rate, and reliability
As n increases, this usually means greater workload capacity and higher production rate
There must be a synergistic effect that derives from n multiple stations working together vs. n single stations

14. System Layout Applies mainly to multi-station systems
Fixed routing vs. variable routing
In systems with fixed routing, workstations are usually arranged linearly
In systems with variable routing, a variety of layouts are possible
System layout is an important factor in determining the most appropriate type of material handling system

15. Automation and Manning Levels
Level of workstation automation
Manually operated
Semi-automated
Fully automated
Manning level Mi = proportion of time worker is in attendance at station i
Mi = 1 means that one worker must be at the station continuously
Mi  1 indicates manual operations
Mi < 1 usually denotes some form of automation

16. Part or Product Variety: Flexibility
“The degree to which the system is capable of dealing with variations in the parts or products it produces”
Three cases:
Single-model case - all parts or products are identical (sufficient demand/fixed automation)
Batch-model case - different parts or products are produced by the system, but they are produced in batches because changeovers are required (hard product variety)
Mixed-model case - different parts or products are produced by the system, but the system can handle the differences without the need for time-consuming changes in setup (soft product variety)

17. Three Cases of Product Variety in Manufacturing Systems
(a) Single-model case, (b) batch model case, and (c) mixed-model case