Overview of Computer-Integrated-Manufacturing (CIM)

by Prabhas Chongstitvatana

lecture for the class ISO 16 Feb 2005

time 1:30 hour

1 Manufacturing enterprises and systems 30 min.

2 Design to Products 30 min.

3 MRP, automation, quality 30 min.

CIM -- A system approach to manufacturing operation in which the planning and control of all activities to build and make a product are supported by computer.

CAD computer-aided design

CAP computer-aided planning

PP&C production planning and control

CAQ computer-aided quality control

CAM computer-aided manufacturing

The tools are models, algorithms, software engineering, data communication, computer interface to man and machines, M2M.

Manufacturing is a collection of interrelated activities that includes product design and documentation, material selection, planning, production, quality assurance, management and marketing of goods.

The fundamental goal of manufacturing is to use these activities to convert raw materials into finished goods on a profitable basis.

A manufacturing strategy is a plan or process that forces congruence between the corporate objectives and the marketing goals and production capability of a company.

<fig 1-4 p.11 order-winning criteria model>

product life cycle

- introduction

- growth

- maturity

- decline

<fig 1-6 p. 14 manufacturing standards>

Cost of doing nothing

1 product life cycle ages

2 price is decreased due to competitive products

3 volume is decreased due to product age

4 overhead is spread over fewer units

5 gross margins drop due to price cuts and overhead costs

Solution

world-class measures

1 design and manufacturing lead time by product

2 inventory turns by product

3 setup times on production equipment

4 production efficiency by product

5 employee output/productivity by product

6 total quality and rework

7 the number of product improvement suggestions per day per employee

CIM is the integration of the total manufacturing enterprise through the use of integrated systems and data communications coupled with new managerial philosophies that improve organisational and personnel efficiency.

<fig 1-8 p.23 manufacturing enterprise wheel>

CIM process

step 1 Assesment of the enterprise in : technology, human resources, systems.

step 2 Elimination of waste

Rules of elimination (3 steps)

(total %)

1 reduce by 50% (50)

2 reduce by 50% again (75)

3 make it 10% of what it originally was (90)

step 3 Implement with performance measure (7 measures above)

Example

Performance report card case history

baseline 6 months 18 months

cycle time 18 weeks 6 weeks 1 week

inventory turns 4 8 48

quality (finished part) 85% 95% 99.8%

floor space 800 ft2 400 ft2 89 ft2

Product development cycle

1 market research

2 management review

3 design engineering

4 production engineering

5 manufacturing

6 customer use

Enterprise organisation

<fig 2-8 p.55 manufacturing organisation>

sales and promotion

finance and management

product/process definition

manufacturing planning and control

shop floor

<fig 2-13 p.61 production sequence>

benefit

<fig 2-15 p.67 enterprise improvement>

Design process

1 conceptualisation

2 synthesis

3 analysis

4 evaluation

5 documentation

- form

- fit (marketing fit)

- function

repetitive design is the application of the design process to a new product by using pieces of previously designed items or small variations from previous designs.

concept design is the application of the design process for the creation of a new product that is unique, with no similarity to any product currently produced.

Synthesis

- design enrichment

- design for assembly

- design for manufacturing

concurrent engineering implies that the design of a product and the systems to manufacture, service, and ultimately dipose of the product are considered from the initial design concept.

<fig 3-13 p.84 traditional product development process>

<fig 3-15 p.86 concurrent engineering >

Production engineering

1 process planning

2 production machine programming

3 tool and fixture engineering

4 work and production standards

5 plant engineering

6 analysis for manufacturability and assembly

7 manufacturing cost estimating

process planning is the procedure used to develop a detailed list of manufacturing operations required for the production of a part or product.

<fig 3-16 p.90 process planning>

<fig 3-17 p.91-92 manufacturing processes>

computer-aided-design

CAD is the application of computers and graphics software to aid or enhance the product design from conceptualisation to documentation.

design for manufacturing and assembly

DFMA is any procedure or design process that considers the production factors from the beginning of the product design.

Ten guidelines for design for assembly (Welter 1989)

1 minimise the number of parts

2 minimise assembly surfaces

3 design for top-down assembly

4 improve assembly access

5 maximise part compliance

6 maximise part symmetry

7 optimise part handling

8 avoid separate fasteners

9 provide parts with integral self-locking features

10 focus on modular design

Design analysis

- static

- dynamic

- natural frequency

- heat transfer

- motion

- fluid

Design verification

- dimensioning, tolerancing

Tolerance analysis

Process planning

<fig 5-23 p.167 example of process planning>

<fig 5-25-26 p.170 process planning system>

<fig 5-33 p.177 APT program>

<fig 5-38 p. 187 enterprise network>

Big picture

Aggregate planning is the generation of a production plan that utilises the enterprise resources efficiently to meet customer demand.

<fig 6-7 p.206 MRP>

<fig 6-8 p.208 input/output of MRP>

<fig 7-1 p.230 production planning>

inventory management

product data management: bill of materials

<fig 7-12 p.240 BOM>

<case study production systems ford + toyota p.256>

JIT is a philosophy of manufacturing based on planned elimination of all waste and on continuous improvement of productivity.

- have only the required inventory when needed

- zero defects

- reduce lead times by: reducing setup times, queue lengths, lot sizes.

- revise incrementally the operations

- accomplish these activities at minimum cost.

zero-inventory manufacturing

waste of over production

waste of waiting

waste of transportation

waste of processing itself

waste of stocks

waste of motion

waste of making defective products

MRP pushes, JIT pulls

<fig 9-9 p.331 future database>

FMS is one manufacturing machine, or mulitple manufacturing machines that are integrated by an automated material handling system, under whose operation is managed by a computerised control system. An FMS can be configured by computer control to manufacture various products.

(Graham 1988)

<fig 10-22 p. 369 FMS>

Five levels of technology in FMS

1 enterprise : scheduling

2 system

3 cell : machine cells, tool gauge, load/unload etc.

4 machine : CNC, testing machines

4 device : motors, sensors

Fixed high volume production

<fig 10-26 p.377-378 rear-axle production line>

Industrial robots

<fig 11-21 p.404 robot survey form>

automated warehousing

<fig 12-2 p.429 cell controller>

work-cell management software

- product monitoring

- process monitoring

- equipment monitoring

- program distribution

- alert and alarm management

- statictical quality and process control

- data and event logger

- work dispatching and scheduling

- tool tracking and control

- inventory tracking and management

- report generator on cell activity

- problem determination

- operator support

- off-line programming

Manufacturing message specification (MMS ISO standard 9506)

Programmable logic controllers (PLC)

<fig 12-12 p.442 PLC>

<fig 12-16 p.447 PLC programming>

six sigma design

process variation and design tolerance

proces variance +- 3 sigma

99.74 % of all production falls +- 3 sigma

(0.26 % lies outside)

<fig 13-15 p.481 six sigma>

if +- 1.5 sigma, 0.62% lies outside

1 million parts defects 6200

+- 5 sigma defects 200 parts per million

+- 6 sigma, near zero defect, a shift of +- 1.5 sigma on critical spec. yields 3.4 defects per million.

The basis for six sigma design is a focuses effort on making the maximum limits on critical dimensional tolerance of parts twice the width of process variability.

J. Rehg and H. Kraebber, Computer-Integrated-Manufacturing, 2nd ed. McGraw Hill, 2001.

U. Rembold, B. Nnaji, A. Storr, Computer integrated manufacturing and engineering, Addison Wesley, 1993.