Operations Final Exam

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Operations Final Exam
2010-06-30 02:45:20
Operations Final Exam

The final exam (Thu, July 1) will be from the following topics: 1. Location Planning slides 11-19; Location Problems ALL slides 2. Process Design n Layout Slides 1-7, 10-36; Layout Problems: ALL slides 3. Inventory Management slides 1-10; Inventory Problems (End of chapter problems 1,4) 4. Lean Enterprise/JIT slides 3-4, 7-10, 18-19, 23, 25-26, 40-41. 5. Project Management slides 1-2, 4-7, 11, 13-19, 26-40.
Show Answers:

  1. Evaluating Locations,
    Cost-Volume-Profit Analysis process:
    • Determine fixed and variable costs
    • Plot total costs
    • Determine lowest total costs
  2. Cost Volume Profit Analysis:
    Lower volumes are best with lower _______Cost
    Higher volumes are best wtih lower _________Cost
    • Fixed
    • Variable
  3. Methods of Evaluating Locations:
    • Transportation Model - Decision based on movement costs of raw materials or finished goods
    • Factor Rating (most popular) - Decision based on quantitative and qualitative inputs
    • Center of Gravity Method - Decision based on minimum distribution costs
  4. Factor Rating/Weighted Score Model:
    • Wi = importance of factor i
    • Si = score of location being evaluated on factor i
    • i = an index for the factors

    Total weighted score = SUMi(Wi)(Si)
  5. Using the Factor Rating Method for Location decisions, the best alternative is the one with?
    Higher composite score
  6. Center of Gravity Method of Location Decisions
    Used for location of Distribution Center
  7. Locating Pure Service Organizations
    • Recipient to Facility
    • -facility utilization
    • -travel distance per citizen
    • -travel distance per visit
    • Facility to Reciplient
  8. Factors that affect Process Selection?
    • 1. Forecasting
    • 2. Products & Service design
    • 3. Technological change
    • 4. Capacity planning
    • 5. Facilities & Equipment
    • 6. Layout
    • 7. Work design
  9. Factors to consider when deciding to make or buy components?
    • 1. Available capacity
    • 2. Expertise
    • 3. Quality consideration
    • 4. The nature of demand
    • 5. Cost
  10. Process Selection based on?
    • Variety - how much
    • Equipment Flexibilty - what degree
    • Volume - expected output
  11. List 5 Process types?
    • 1. Job Shops (small runs)
    • 2. Batch Processing
    • 3. Repetitive/Assembly (semicontinuous)
    • 4. Continuous Process
    • 5. Projects (nonroutine jobs)
  12. This process type is low volume, high variety, high flexibility?
    Job Shop
  13. This process is moderate volume, moderate variety, moderate flexibility?
  14. This process is High Volume, Low Variety, Low Flexibility?
    Repetitive Assembly (Line)
  15. This process is very high volume, very low variety, very low flexibility?
  16. Describe Layout
    The configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system.
  17. Three basic layout types?
    • 1. Product Layouts
    • 2. Process Layouts
    • 3. Fixed-Position
  18. Describe Product Layout and which processes use it?
    • Product Layout uses standardized processing operation to achieve smooth, rapid, high volume flow.
    • Line, Continuous
  19. Describe Process Layout and which processes use it?
    • Process layout can handle varied processing requirements.
    • Job Shop or Batch (ex: hospital)
  20. Describe Fixed-Position Layout and process that uses it?
    • Fixed Position is a layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed.
    • Project Ex: Building or freeway
  21. Importance of Layout Decisions?
    • 1. Requires substantial investments of money and effort
    • 2. Involves long-term commitments
    • 3. Has significant impact on cost and efficiency of short-term operations
  22. Eight things that cause a need for layout decisions?
    • 1. Inefficient operations (ie: hi cost bottlenecks)
    • 2. Changes in the design of products or services
    • 3. The introduction of new products or services
    • 4. Accidents/Safety hazards
    • 5. Changes in environmental or other legal requirements
    • 6. Changes in volume of output or mix of products
    • 7. Changes in methods and equipment
    • 8. Morale problems
  23. Layout Formats?
    • 1. Group Technology Layout
    • 2. Just-In-Time Layouts
    • -May be assembly-line or
    • -Group Technology formats
    • 3. Fixed Position Layout
    • -eg Shipbuilding
  24. Cellular Layouts include?
    • 1. Cellular Manufacturing
    • 2. Group Technology
    • 3. Flexible Manufacturing Systems
  25. The advantage of Cellular Layouts?
    • They retain flexibility in the process and gain economies of scale.
    • Ex: Lazyboy Case
  26. Explain Cellular Manufacturing?
    Layout in which machines are grouped into a cell that can process items that have similar processing requirements.
  27. Explain Group Technology Layout?
    The grouping into part families of items with similar design or manufacturing characteristics.
  28. A Flow Line for Production or Service
  29. A U-Shaped Production Line
  30. Adavantages of U-Shaped Production Line?
    • 1. Shorter distance
    • 2. Workers can alternate tasks
    • 3. Shipping & Receiving can be in 1 place
  31. Describe Process Layout?
    • Departmentalized process where work travels to dedicated process centers
  32. Functional Layout
  33. Cellular Manufacturing Layout
    • Part families are based on Group Technology
    • -minimizes material movement
    • -efficient, but still flexible
  34. Line Balancing
    is the process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements.
  35. Cycle Time
    is the maximum time allowed at each workstation to complete its set of tasks on a unit.
  36. Determine maximum Output
  37. Determine the minimum number of workstations required: Efficiency
  38. Precendence Diagram
    Tool used in line balancing to display elemental tasks and sequence requirements.
  39. Calculation for Percent Idle Time
  40. Line Balancing Rules
    Hueuristic (intuitive) Rules
    • Assign tasks in order of most following tasks
    • Assign tasks in order of greatest positional weight (positional weight is the sum of each task's time and the stimes of all following tasks)
  41. Parallel Workstations
  42. Design Process Layouts Requirements
    • List of departments
    • Projection of work flows
    • Distance between locations
    • Amount of money to be invested
    • List of special considerations
  43. What is Inventory?
    • A Liability (idle resource held for future use
    • A Stock Keeping Unit (any entity that a company identifies for the purpose of control)
  44. Types of Inventory (4)
    • Finished goods
    • Work in Progress
    • Raw Materials
    • Spare Parts
  45. Functions of Inventory (7)
    • To meet future demand
    • To avoid stockouts
    • To meet demand in case of breakdown of equipment
    • Hedge against price increases
    • Decouple production and distribution
    • Decouple two operations
    • Decouple Production & Suppliers
  46. Two basic questions of Inventory Management
    • How much to order
    • When to order
  47. Independent demand
    An item whose demand can be forecasted (estimated)
  48. Dependent Demand
    Demand related to the demand of other items (easier to manage, can be calculated)
  49. ABC Classification
    This method will allow you to identify the small amount of products that usually account for most of your sales dollars (think 80/20 rule)
  50. Relevant Inventory Costs
    Costs increase with inventory...
    Inventory Carrying Costs
  51. Examples of Inventory Carrying Costs (6)
    • Cost of invested funds (interest, dividends)
    • Cost of Storage Space (rent, heat/cool, etc)
    • Taxes and Insurance
    • Quality Costs (defective units)
    • Coordination Costs (lg lots, diff coord)
    • Loss of Poor Responsiveness (obsolescence)
  52. Relevant Inventory Costs
    Costs decrease with inventory...
    • Ordering Costs (Cost to place order, receive & inspect) Fixed $ amt/order
    • Setup Costs (item manufactured in-house)
    • Cost of missed sales (loss of goodwill, oppty cost)
  53. EOQ Basic Assumptions (6)
    • Demand is known and constant
    • Lead time is known and constant
    • Receipt of inventory is instantaneous
    • Quantity discounts are not possible
    • The only variable costs are the cost of setting up or placing an order, and the cost of holding or storing inventory over time.
    • Stockouts can be completely avoided if orders are placed at the appropriate time.
  54. Formula for EOQ
    • Sqrt 2DS/H
    • D=Annual Demand
    • S=Order Cosst per year
    • H=Holding Cost $/unit/yr
  55. 1) Average inventory =
    2) # orders in a year =
    3) Total Cost
    4) Derrivative EOQ Formula
    • 1) 1/2Q
    • 2) D/Q
    • 3) Inventory Carrying Cost + Order Cost
    • 4) 1/2Q*H + D/Q*S
  56. For C-Class items, the quantity is not fixed, the ________is?
    period (Fixed Period Review)
  57. Fixed order vs. Fixed period
  58. Other model of inventory
    • Two Bin System
    • Reorder point is when first bin is empty
  59. What is Lean Production?
    a socioethical production system whose main objective is to eliminate waste by concurrently reducing or minimizing supplier, customer and internal variability.
  60. Toyota Production System (TPS) idea
    is to produce the kind of units needed, at the time needed, and in the quantities needed, so that unnecessary intermediate and finished product inventories can be eliminated.
  61. Lean thinking is more than a set of techniques and approaches, it is...
    a mindset for all employees and managers that focuses on waste eliminationand variability reduction in all business processes.
  62. Who is credited with developing the original principles behind lean thinking?
    Henry Ford wiht the Ford Production System (FPS)
  63. Japanese Manufacturing approaches that drew the attention of US Manufacturers in the 70's during the US Oil Crisis
    • TPS
    • JIT
    • Kanban
    • Kaizen
  64. JIT Lean Production
    • Just-in-time (JIT) is a characteristic of lean production systems.
    • JIT is a repetitive production system in which processing and movement of materials and goods occur just as they are needed, usually in small batches.
    • JIT operates with very little fat.
  65. Three tenets of JIT
    • 1. Eliminate waste
    • 2. Total quality management
    • 3. People involvement
  66. Sources of waste (6)
    • Operproduction
    • Waiting time
    • Unnecessary transportation
    • Processing waste
    • Inefficient work methods
    • Product defects
  67. Big JIT
    • Broad focus
    • -Vendor relations
    • -Human relations
    • -Technology management
    • -Materials and inventory management
  68. Little JIT
    • Narrow Focus
    • -Scheduling materials
    • -Scheduling services of production
  69. Pull System
    System for moving work where a workstation pulls output from the preceding station as needed (ex: Kanban)
  70. Push System
    System for moving work where output is pushed to the next station as it is completed.
  71. Kanban Production Control System (4)
    • Kanban is a card or other device that communicates demand for work or materials from the preceding station.
    • Japanese word meaning signal or visible record.
    • Paperless production control system.
    • Authority to pull, or produce comes from a downstream process.
  72. JIT in Service (describe & 6 points)
    • GOAL: to provide optimum response to the customer with the highest quality service and lowest possible cost.
    • -Eliminate disruptions
    • -Make system flexible
    • -Reduce setup and lead times
    • -Eliminate waste
    • -Minimize WIP
    • -Simplify the process
  73. Benefits of JIT Systems (5)
    • Reduced inventory levels
    • High quality
    • Flexibility
    • Reduced lead times
    • Increased productivity
  74. Benefits of JIT continued (5)
    • Increased equipment utilization
    • Reduced scrap and rework
    • Reduced space requirements
    • Pressure for good vendor relationships
    • Reduced need for indirect labor
  75. Kaizan
    Japanese term that means contiuous improvement
  76. Quality at the Source
    a practice in which each employee is responsible for thie quality of his or her own work, therefore each person acts as his or her own quality inspector.
  77. Jidoka
    An approach for automated quality monitoring of equipment guided by a human touch.
  78. Concurrent Engineering
    a process in which multiple units/departments within an organization/supply chain are committed to working interactively to conceive, approve, develop and implement new product development programs that meet predetermined objectives.
  79. Elements of Project Management (3)
    • What is a project?
    • What is Project Management?
    • Role of the Project Manager
  80. What is a Project?
    A set of interrelated activities necessary to achieve established goals using a specified amount of time, budget, and resources.
  81. Primary characteristics of a Project? (6)
    • A well-defined goal or objective
    • Composed of a set of interrelated activities
    • A specified beginning and ending time
    • Specified resource and personnel requirements
    • A specified budget
    • Uniqueness
  82. Project Applications (4)
    • Strategic projects
    • Intermediate range projects
    • Short-term projects
    • Personal life projects
  83. Examples of Operations Management Projects (3)
    • Developing new product offerings, ex: Wii, etc
    • Quality Improvement Projects, ex: Six Sigma
    • Preparation for ISO9000 certification
  84. Project Management is...
    Application of the knowledge, skills, tools, and techniques necessary to successfully complete a project.
  85. According to PMI (Proj Mgmt Inst), project management can be divided into 5 categories...
    • Initiation
    • Planning
    • Execution
    • Control
    • Closure
  86. Project Life Cycle (project phases) (4)
    • Conceptualizing - need
    • *Planning - activities, sequence, time
    • Organizing/Scheduling - details
    • Executing/Control - trade-off: resources vs. time

    *most time spent in the planning phase
  87. Project Planning, Work Breakdown Structure (WBS)
    Divides total work into major work packages to be accomplished, with the key being to get to the smallest possible detail.
  88. Project Scheduling methods (2)
    • PERT - Program Evaluation and Review Technique
    • CPM - Critical Path Method
  89. PERT
    • Used for projects that have never been done before
    • Optimistic / Most Likely / Pessimistic
    • ~Beta Distribution
    • EX: Polaris Missile
  90. CPM
    Critical Path Method is an algorithm for scheduling activities within a project for the fastest and most efficient execution.
  91. Critical Path (within CPM)
    • the path within a project that takes the longest time to complete.
    • - Dictates the project completion time
    • - aka: the bottleneck path or the binding constraint
  92. Critical activities
    the project activities making up a critical path
  93. Slack (associated with CPM)
    the amount of flexibility in scheduling an activity within a project.
  94. Gantt Chart
    • A special type of horizontal bar chart used to display the schedule for an entire project.
    • Named after Henry Gantt who originated the chart in the 1910s
    • A Gantt Chart with different color codes can be used to track performance while the project is in progress.
  95. Network Diagram
    A diagram with arrows and nodes created to display a sequence of activities within a project.
  96. Activity on Node (AON) approach
    A network diagram that shows each activity as a circle (or a node) and connects the activities with arrows.
  97. Activity on Arrow (AOA) convention
    A network diagram in which each activity is represented by an arrow, and the nodes are used to show the beginning and end points.
  98. Precendence Relationship
    Some activities cannot be performed until other activities have been completed.
  99. Determining the Critical Path in a network diagram
    • Forward pass (ES: Early Start)
    • Backward pass (LF: Late Finish)
    • Calculate Slack:
    • EF= ES + activity time
    • LS = LF - activity time
    • Slack = (LS-ES) or (LF-EF)
  100. Slack (Network Diagram)
    Amount of time an activity can be delayed beyond its earliest possible starting time without delaying the project completion.
  101. Critical Path (Network Diagram)
    • A chain of sequential activities beginning at the project's start and ending at its completion with the longest elapsed time.
    • has a maximum duration compared to other paths in the network
    • all activities on the critical path have zero slack
  102. Project Scheduling when activity times are known
    Inputs (2)
    Outputs (5)
    • activity completion times
    • activity precedence relationships

    • graphical representation of project
    • time to complete project
    • identification of critical path(s) and activities
    • activity and path slack
    • earliest start, earliest finish, latest start,a nd latest finish times for each activity
  103. Path Slack
    Duration of Critical Path - Path Duration = Path Slack
  104. Program Evaluation and Review Technique (PERT)
    • A technique for addressing the impact of uncertainties in activity time estimates on the duration of the entire project.
    • In a project schedule, different estimates for activity times are developed: Optimistic (tO), Pessimistic (tP), Most Likely (tM), Expected (tE)
  105. Project Scheduling when activity times are uncertain
    Inputs (2)
    Outputs (4)
    • Optimistic (tO), Most Likely (tM), and Pessimistic (tP) time estimate for each activity
    • Activity precedence relationships

    • Graphical representation of project
    • Expected activity and path completion times
    • Variance of activity and path completion times
    • Probability that project completed by specified time
  106. Expected Activity Time and Variance of Activity Time formulas