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Production & Operations ManagementChapter : The Role of Operations Management
Business Process Reengineering
Inventory Management
Operations Strategy
Total Quality Management
Supply Chain Management
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Planning & Control
Analyzing Operations
New Product/process development
Project Management
Issues For International Operations
Time Based Competition
Cost Elements
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Start Questioning operations productivity
Eliminating unuseful operations
CombinIing operations
Improving Operations Productivity
(Re) Design of new processes
Discussing the 9 primary approches to Operations Analysis
Lecture Outlines
1. Operation Purpose
2. Part Design
3. Tolerances and Specs
4. Material
5. Manufacturing Sequence and Process
6. Setup and Tools
7. Material Handling
8. Plant Layout
9. Work Design
Operation Purpose
Ask:
“Does this operation serve a useful purpose?”“Is this operation really needed?”
Try to:
Eliminate operationsCombine operations
As many as 25% of operations in American Industry can be eliminated.
Example 1 : Operation Elimination
Many stores have dropped the requirement that customers sign their credit slip for small totals: less than $15 - $50.
This makes the payment transaction very fast!E.g. in coffee shop study,
Average payment transaction time: 27 sec
Example 2 : Operation Elimination Outsource operations
Ask: “Can a supplier an operation more economically than we can in-house?”
Operation: pack ball bearings in grease
Modification: purchase sealed bearings from supplier.
Example 3 : Operation Elimination Eliminate re-workCoffee shop worker:Worker pours milk into stainless steel beaker,Steams milk, pours into cup.Runs out of milk – must pour and steam more while customer waits impatiently.
Solution: Add measuring lines to inside of beaker so worker does not have to estimate how much milk to pour.
Part DesignDesign for manufacturing and life-Cycle
Reduce parts – simplify designs
Reduce processing operations
Utilize better material
Loosen tolerances where possible
Design for manufacturing: choose an easy to manufacture shape over a difficult one.
Minimum cost design
It helps designers if they understand processes such as: casting, molding, bending, etc.Example: instead of:
Four bends in sheet metal to make part, Make lower cost extrusion with 4 bends already
in it.
This type of thinking is called
“Design for Manufacturing”
Tolerances and specifications
Designers tend to incorporate tolerances that are more rigid than necessary
Why? To be extra sure that product will function in all situations.
It is perceived to reduce risk, but it can add much unnecessary cost,
Need to consider risk/cost trade-off.
Taguchi (86) methods develop quality products and reduce cost.
Material
Incorporate better, more economical material in designs:
Less expensiveEasier to processUse materials more economicallyUse supplies and tools more economically,Standardize materialsFind best vendor: price, stock. Can achieve
10% to 15% reductions by shopping around, sometimes every year.
Example: New material
Replace stamped gear with plastic gear in assembly. saved $0.13 per unit, $10,000 per year.
Keiretsu: (Japanese term) interlocking relationship between manufacturers and suppliers.
Manufacturing Sequence and Tools
Re-sequence operations Group operations that can share common fixturingMechanize manual operations where economically feasible (see section on setup)Use more efficient facilities (see section on layout) Example, substitute Super automatic cappuccino machines for old style.Manufacture near-net shape.Use Robots (where economically feasible – usually for long product runs, small product variability)
Example: re-sequencing
Original sequence:• Paint part 1• Paint part 2• Paint part 3• Paint part 4• Rivet parts together
New sequence:• Rivet parts together• Paint one assembly
Setup, Tools and Fixtures
Carefully consider economic trade-offs:
Will the setup, fixtures, or tools be used enough to justify their expense?
Prevalent mistake of tool makers and planners:Too much specialized tooling and fixturing
Example: Tooling
Good choice: Tooling that saves 10% on each job and is used frequently.
Poor choice: Tooling that saves 90% on each job but is used only twice a year. (Will not recover expense of creating and storing tooling).
Material Handling
The best way to handle material is NOT to handle it.
Moving, storing, positioning, tracking.Insuring that materials get where they need to be when they are needed.Material Handling Institute survey says 35 to 85% of the cost of getting a product to market is associated with material handling.
Better Material Handling
Reduces cost, time
Increases safety, health and well being of workers:
40% of plant accidents happen during material handling
25% are caused by lifting and shifting material
Approach to reducing material handling time
Reduce time spent picking up material
Use mechanized of automated equipment (where economically feasible)
Make better use of existing handling facilities
Handle material with greater care
Consider bar coding
Plant Layout
Poor layout can result in major costs through increased travel time, increased material handling, etc.
Two types of layouts for plants:Product layout: machines placed in the order used in
the manufacturing process. Advantage: reduces travel time
Process layout: machines grouped by type: e.g. all lathes together, all drill presses together, etc.
Advantage: makes training easier.
Later we will discuss Muther’s Systematic Layout Process (SLP).
Work Design
Eliminate operations,Re-sequence, re-design operations
Many of our remaining chapters focus on many different types of work design!
Muther’s (1973) Systematic Layout Process (SLP)
Goal: identify how to rearrange space to make it more effective for a task.
1. Chart out relationships between areas based on magnitude of material handling,
2. Establish space requirements,3. Make activity relationship diagrams4. Space relationship layout5. Evaluate alternative layouts6. Select best layout, plan installation.
Decision Matrices
“Goodness” score for each option i is Σ (importance weight j * performance score i j)
Renovation
Cost
Material handling cost Use of Space Aesthetics
Goodness Score
importance(1 -
least, 10 -
most) 8 10 5 7
Option 1 3 3 4 2 88
Option 2 4 3 4 1 89
Option 3 2 4 3 3 92
Performance Parameters
A PM is whatever is important to the decision maker in the situation,
Select the best layout for your purposes
Choose the Layout with the highest “score” from your decision matrices
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2.
3.
88
89
92Best!
THANK YOU!
Ahmed BELAFQUIH