Chapter 3: Operation Analysis

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Chapter 3 Operation Analysis

• Human Factors
• Prof. Hayes

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If Methods Engineering Focuses Primarily on
improving productivity though (re)design of
Motivation Incentives/rewards
Organizational structure
Work Process
Work operations
Tools (Products)
Work environment
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Then Operations Analysis Focuses Primarily on
improving productivity though (re)design of
Motivation Incentives/rewards
Organizational structure
Work Process
Work operations
Tools (Products)
Work environment
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The 9 Primary Approaches to Operation Analysis

• Operation Purpose
• Part Design
• Tolerances and Specs
• Material
• Manufacturing Sequence and Process

• Setup and Tools
• Material Handling
• Plant Layout
• Work Design

Also consider management and reward changes
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Simultaneously consider many ways of making
improvements!
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1. Operation Purpose

• Ask
• Does this operation serve a useful purpose?
• Is this operation really needed?
• Try to
• Eliminate operations
• Combine operations
• As many as 25 of operations in American Industry
  can be eliminated.

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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

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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.

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Example 3 Operation Elimination Eliminate re-work

• Coffee 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.

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2. 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.

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Minimum cost design

• It helps designers if they understand processes
  such as casting, molding and punching, 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

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3. 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.

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4. Material

• Incorporate better, more economical material in
  designs
• Less expensive
• Easier to process
• Use materials more economically
• Use supplies and tools more economically,
• Standardize materials
• Find best vendor price, stock. Can achieve 10
  to 15 reductions by shopping around, sometimes
  every year.

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Example New material

• Substitute glass tubing for Micarta spacer bar in
  transformer. (Micarta is a glass cloth, epoxy
  resin laminate material)
• ? less expensive and better cooling
• 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.

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5. Manufacturing Sequence and Tools

• Re-sequence operations
• Group operations that can share common fixturing
• Mechanize 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)

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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

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6. 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

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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).

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7. 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.

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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

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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

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8. 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 Muthers Systematic Layout
  Process (SLP).

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9. Work Design

• Eliminate operations,
• Re-sequence, re-design operations
• Many of our remaining chapters focus on many
  different types of work design!

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Muthers (1973) Systematic Layout Process (SLP)

• Goal identify how to rearrange space to make it
  more effective for a task.

• Chart out relationships between areas based on
  magnitude of material handling,
• Establish space requirements,
• Make activity relationship diagrams

• Space relationship layout
• Evaluate alternative layouts
• Select best layout, plan installation.

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Decision Matrices
A performance parameter is whatever is important
to the decision maker in the
situation, Goodness score for each option i is
S (importance weight j performance score i j)
Performance Parameters
Performance score, where 4 best, -1
unacceptable
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6. Select the best layout for your purposes

• Choose the Layout with the highest score from
  your decision matrices

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Best!