1. Unit 2 Manufacturing Operations
Sections:
Manufacturing Industries and Products
Manufacturing Operations
Production Facilities
Product/Production Relationships
Lean Production
Manufacturing Metrics
Manufacturing Lead Time
Rate of Production
Production Capacity
Work in Progress
Design Times
Utilisation/Availability

2. Classification of Industries
Primary industries – cultivate and exploit natural resources
Examples: agriculture, mining
Secondary industries – convert output of primary industries into products
Examples: manufacturing, power generation, construction
Tertiary industries – service sector
Examples: banking, education, government, legal services, retail trade, transportation

3. Manufacturing Industries
ISIC Code
Food, beverages, tobacco
Textiles, apparel, leather and fur products
Wood and wood products, cork
Paper, printing, publishing, bookbinding
Chemicals, coal, petroleum, & their products
Ceramics, glass, mineral products
Basic metals, e.g., steel, aluminum
Fabricated products, e.g., cars, machines, etc
Other products, e.g., jewelry, toys

4. More Industry Classifications
Process industries, e.g., chemicals, petroleum, basic metals, foods and beverages, power generation
Discrete product (and part) industries, e.g., cars, aircraft, appliances, machinery, and their component parts

5. Process Industries and Discrete Manufacturing Industries

6. Manufacturing Industry
Transformation Operations
Machine Processing
Assembly
Adding value*
Other Operations
Material handling
Inspection and testing
Coordination and control
Raw
Material
Part or
Product
Transformation Process
Scrap or
Waste
Power
Tools
Machines
Labour

7. Classification of manufacturing processes

8. Processing Operations
Shaping operations
Solidification processes
Particulate processing
Deformation processes
Material removal processes
Property-enhancing operations (heat treatments)
Surface processing operations
Cleaning and surface treatments
Coating and thin-film deposition

9. Assembly Operations Joining processes Welding Brazing and soldering
Adhesive bonding
Mechanical assembly
Threaded fasteners (e.g., bolts and nuts, screws)
Rivets
Interference fits (e.g., press fitting, shrink fits)
Other

10. Material Handling Material transport
Vehicles, e.g., forklift trucks, AGVs, monorails
Conveyors
Hoists and cranes
Storage systems
Unitizing equipment
Automatic identification and data capture
Bar codes
RFID
Other AIDC

11. Time Spent in Material Handling

12. Inspection and Testing
Inspection – conformance to design specifications
Inspection for variables - measuring
Inspection of attributes – gauging
Testing – observing the product (or part, material, subassembly) during operation

13. Coordination and Control
Regulation of the individual processing and assembly operations
Process control
Quality control
Management of plant level activities
Production planning and control

14. Production Facilities and Layout
Facilities organised in the most efficient way to serve the particular mission of the plant and depends on:
Types of products manufactured
Production quantity
Product variety

15. Production Quantity (Q)
Number of units of a given part or product produced annually by the plant
Three quantity ranges:
Low production – 1 to 100 units
Medium production – 100 to 10,000 units
High production – 10,000 to millions of units

16. Product Variety (P)
Number of different product or part designs or types
‘Hard’ product variety – products differ greatly
Few common components in an assembly
‘Soft’ product variety – small differences between products
Many common components in an assembly

17. Product Variety (P) vs. Production Quantity (Q)

18. Low Production Quantity (Qlow)
Job shop – makes low quantities of specialized and customized products
Products are typically complex (e.g., specialized machinery, prototypes, space capsules)
Equipment is general purpose
Plant layouts:
Fixed position
Process layout

19. Fixed-Position Layout

20. Process Layout

21. Medium Production Quantities (Qmed)
Batch production – A batch of a given product is produced, and then the facility is changed over to produce another product
Changeover takes time – setup time
Typical layout – process layout
Hard product variety
Cellular manufacturing – A mixture of products is made without significant changeover time between products
Typical layout – cellular layout
Soft product variety

22. Cellular Layout

23. High Production (Qhigh)
Quantity production – Equipment is dedicated to the manufacture of one product
Standard machines tooled for high production (e.g., stamping presses, molding machines)
Typical layout – process layout
Flow line production – Multiple workstations arranged in sequence
Product requires multiple processing or assembly steps
Product layout is most common

24. Product Layout

25. PQ Relationships P Q

26. Product Quantity and Variety
Let Qj = annual quantity of variety ‘j’
P = variety of products from ‘1’ to ‘j’
Total number of product units = Qf =

27. Product and Part Complexity
Product complexity np = number of components in product
Part complexity no = number of processing operations per part

29. Factory Operations Model
Simplified :
Total number of product units Qf = PQ
Total number of parts produced npf = PQnp
Total number of operations nof = PQnpno
where
P = Product variety
Q = Product quantity
np = Number of parts in product
no = Number of operations in product

30. Worked Problem
2.2: The ABC Company is planning a new product line and will build a new plant to manufacture the parts for a new product line. The product line will include 50 different models. Annual production of each model is expected to be 1000 units. Each product will be assembled of 400 components. All processing of parts will be accomplished in one factory. There are an average of 6 processing steps required to produce each component, and each processing step takes 1.0 minute (includes an allowance for setup time and part handling). All processing operations are performed at workstations, each of which includes a production machine and a human worker. If each workstation requires a floor space of 250 m2, and the factory operates one shift (2000 hr/yr), determine (a) how many production operations, (b) how much floorspace, and (c) how many workers will be required in the plant.

31. Solution This problem neglects the effect of assembly time:
(a) nof = PQnpno = 50(1000)(400)(6) = 120,000,000 operations in the factory per year.
(c) Total operation time = (120 x 106 ops)(1min./(60 min./hr)) = 2,000,000 hr/yr.
At 2000 hours/yr per worker, w = = 1000 workers.
(b) Number of workstations n = w = 1000.
Total floorspace = (1000 stations)(250 m2/station) = 250,000 m2

32. Manufacturing Capability
Technological processing capability - the available set of manufacturing processes
Physical size and weight of product
Production capacity (plant capacity) - production quantity that can be made in a given time

33. Lean Production
Operating the factory with the minimum possible resources and yet maximizing the amount of work accomplished
Utilisation of Resources - workers, equipment, time, space, materials
Minimising time
Maximising quality (accuracy)
Minimising cost
Doing more with less, and doing it better

34. Programs Associated with Lean Production
Just-in-time delivery of parts
Worker involvement
Continuous improvement
Reduced setup times
Stop the process when something is wrong
Error prevention
Total productive maintenance

35. Problem 2.4
The XYZ Company is planning to introduce a new product line and will build a new factory to produce the parts and assembly the final products for the product line. The new product line will include 100 different models. Annual production of each model is expected to be 1000 units. Each product will be assembled of 600 components. All processing of parts and assembly of products will be accomplished in one factory. There are an average of 10 processing steps required to produce each component, and each processing step takes 30 sec. (includes an allowance for setup time and part handling). Each final unit of product takes 3.0 hours to assemble. All processing operations are performed at work cells that each includes a production machine and a human worker. Products are assembled on single workstations consisting of two workers each. If each work cell and each workstation require 200 ft2, and the factory operates one shift (2000 hr/yr), determine: (a) how many production operations, (b) how much floorspace, and (c) how many workers will be required in the plant.
If the company were to operate three shifts (6000 hr/yr) instead of one shift, determine the answers to (a), (b), and (c).

36. Solution Solution: (a) Qf = PQ = 100(1000) = 100,000 products/yr
Number of final assembly operations = 100,000 assy.opns/yr
Number of processing operations nof = PQnpno = 100(1000)(600)(10) = 600,000,000 proc.opns/yr
(c) Total processing operation time = (600 x 106 ops)(0.5 min./(60 min./hr)) = 5,000,000 hr/yr.
Total assembly operation time = (100 x 103 asby ops)(3 hr/product) = 300,000 hr/yr
Total processing and assembly time = 5,300,000 hr/yr
At 2000 hours/yr per worker, w = = 2650 workers.
(b) With 1 worker per workstation for processing operations, n = w = 2500 = 2500 workstations.
With 2 workers per stations for assembly, n = w/2 = 150/2 = 75 workstations.
Total floor space A = (2575 stations)(200 ft2/station) = 515,000 ft2

37. Solution
(a) Same total number of processing and assembly operations but spread over three shifts.
Number of final assembly operations = 100,000 assy.opns/yr
Number of processing operations nof = PQnpno = 100(1000)(600)(10) = 600,000,000 proc.opns/yr
(c) Same total number of workers required but spread over three shifts.
Total workers w = 2650 workers. Number of workers/shift = w/3 =  884 workers/shift.
(b) Number of workers for processing operations = 2500/3 = 833 worker per shift (884 on one shift)
Number of workers for assembly = 150/3 = 50 workers per shift.
Number of workstations n = /2 = 858 (859 on one of the shifts).
Using the higher number, Total floor space A = (859 stations)(200 ft2/station) = 171,800 ft2