Operations Midterm 4

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Operations Midterm 4
2012-02-07 21:49:06
operations midterm

Operations Midterm Ch 4
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  1. Variation of flow time exists based on the flow unit
    what is being measured

    i.e. the rate of putting lugnuts on wheel much different then rate of putting wheel on axel
  2. Why process flow is a valuable process performance measure
    Flow time directly affects delivery response time

  3. Short flow times are good because (4):
    • 1. For customer's, less wait = more value
      2. Short delivery time = more cash flow
    • 3. Reduction of inventory
    • 4. Faster "to market" performance (first mover advantage, earlier correction of issues from customer feedback)
  4. Flow time can be determined by two ways:
    • Direct observation
    • Little's Law
  5. Direct Observation (flow time measurement)
    • Observe process over predetermined/extended period of time
    • Select random flow units
    • Measure flow time from entry to exit
    • Compute average of flow times
  6. Little's Law (flow time measurement)
    Average Inventory = Throuhgput x Flow Time

    • Observe process over predetermined/extended period of time
    • Select random flow units
    • Measure actual inventory within boundaries of each time point
    • Compute average inventory
  7. Market differences in flow time
    Club Store (Sam's Club) - only about 5 touches from production to shelf vs Drug Store (CVS) up to 20 touches
  8. Flow Time Measurement - ensure
    • Clear understanding of what you wnat to measure
    • Clear definition of flow units
    • Clear on entry and exit points
    • Hold components consistent over time
  9. Flow Time minimum
  10. Critical Path
    Longest path in a process

    This must be reduced to reduce overall flow time, improve process.
  11. Theoretical Flow Time
    Minimum amount of time for a flow unit to pass through process if there was no waiting or disruption
  12. Key roles of manager regarding Theoretical Flow Time
    • 1. Minimize this
    • 2. Minimize waiting and disruption (braks, web surfing, water cooler, etc.)
  13. Ways to Shorten Critical Path
    • Work in Paralell
    • Work Smarter
    • Do it right the first time
    • Work faster
  14. move work off critical path
    work in paralell
  15. Eliminate non value add activities (activities that customer will pay for)
    Work smarter
  16. reduce re-work
    do it right hte first time
  17. Non value add activities examples
    meetings, obtaining approvals, filling out forms
  18. Two types of non value add activities
    Necessary to support process - internal accounting system

    Not Necessary to support process (should be eliminated) - process improvement - automation does this (data entry clerks become obsolete when systems are set up)
  19. Modify product mix (shorten critical path)
    difficult as product mix is normally based on customer needs not internal processes
  20. flow chart
    graphical representation of process