Chapter 17—Lean Operating SystemsTRUE/FALSE 1. Lean enterprise refers to approaches that focus on the elimination of defects and errors throughout the value chain. ANS: F PTS: 1 2. In lean thinking, waste need not be classified as simply material waste such as scrap and defective parts. ANS: T PTS: 1 3. Synchronization of the value chain is a lean approach to increasing speed and response. ANS: T PTS: 1 4. According to the Toyota Motor Company, waiting time is a necessary evil in production and is not classified as waste. ANS: F PTS: 1 5. The 5Ss focus on improving waste generated by inefficient transportation. ANS: F PTS: 1 6. Firms use the “5S” principles to create a clean and organized work environment. ANS: T PTS: 1 7. A clean and organized work area is an important principle of lean thinking. ANS: T PTS: 1 8. Single minute exchange of dies (SMED) frees up capacity for other productive uses. ANS: T PTS: 1 9. Large batches often provide economies of scale and helps firms match inventory to market demand. ANS: F PTS: 1 10. To accomplish single piece flow, a manufacturer needs the ability to change between products quickly and inexpensively. ANS: T PTS: 1 11. Lean operating systems seek to apply the principles of continuous flow to the production of discrete parts by reducing batch size, ideally to a size of one. ANS: T OM3 Test Bank PTS: 1 Chapter 17 1 JIT systems are based on the concept associated with pull systems rather than push systems. each of which has been used independently in other applications. lean production is more concerned with less visible problems. ANS: T PTS: 1 23. finished goods inventory is produced in advance of customer demand using a forecast of sales. ANS: T PTS: 1 15. ANS: F PTS: 1 16. ANS: T PTS: 1 13. Lean Six Sigma is simply the union of lean approaches with quality improvement techniques. Lean production is focused on efficiency by reducing waste and improving process flow. The number of Kanban cards is directly proportional to the amount of work-in-process inventory. Lean principles are of primary benefit to manufacturers and provide little value to service organizations. ANS: F PTS: 1 17. Six Sigma addresses visible problems in processes. ANS: F PTS: 1 14. ANS: T PTS: 1 18. Production Kanbans trigger the movement of parts. while Six Sigma is focused on effectiveness by reducing errors and defects. A goal of total productive maintenance is to have zero accidents in the entire life cycle of the operating system. ANS: F PTS: 1 20. ANS: T PTS: 1 19. ANS: T PTS: 1 21. Kanban is a Japanese term for elimination of waste. In a JIT system. OM3 Test Bank Chapter 17 2 .12. In a push system. The goal of total productive maintenance is to minimize the costs associated with routine maintenance activities. ANS: F PTS: 1 22. the computer inventory data is the interface and control point between customers and supply cycles. In the 5Ss. Elimination of waste b. Transportation ANS: C PTS: 1 4. Batching c.ANS: F PTS: 1 24. Standardize OM3 Test Bank Chapter 17 3 . ANS: F PTS: 1 25. Single-piece flow ANS: D PTS: 1 3. Sustain ANS: A PTS: 1 5. Overproduction b. which of the following is not one of the seven major waste categories? a. Overproduction b. ANS: F PTS: 1 MULTIPLE CHOICE 1. Waiting time d. Which of the following is not a basic principle of a lean operating system? a. Which of the following is not one of the 5Ss? a. According to the Toyota Motor Company. Standardize c. Synchronize c. Synchronize b. Sort b. the ideal strategy is to run large batches. Total Productive Maintenance (TPM) strives to relieve machine operators of routine maintenance so that they can focus entirely on being productive. Shine d. Single-piece flow c. Shine d. Long lead-times and higher work-in-process is most closely related to which of Toyota's "Seven Major Waste Categories?" a. Transportation c. Motion d. Increased speed and response d. When producing a broad goods or service mix with diverse requirements on common equipment. items identified as unnecessary and thus removed from a workplace would be included with which S? a. Improved quality ANS: B PTS: 1 2. Puts total responsibility on equipment operators c. Doing it right the first time d. Enable multiple products in small batches to be run on the same equipment ANS: D PTS: 1 9. Total Production Maintenance (TPM) a. 5Ss d. Quick setup or changeover of tooling and fixtures is associated with ____. a. Building inventory b. Visual controls b. Having reliable suppliers c. Maximum customer responsiveness b. Create worker ownership c. Which of the following is least related to a push system? a. Quality at the source requires a. a. Having a good design ANS: C PTS: 1 10. Total productive maintenance (TPM) seeks to do all of the following except ____. Eliminates all down time d. Final assembly schedule c. Which of the following is least related to a pull system? a. Predefined schedule c. Single minute exchange of dies c. Waiting ANS: B PTS: 1 11. Those categories include all of the following except a. Employees preserve and protect their equipment ANS: D PTS: 1 8. Ordering c. Puts total responsibility on maintenance workers b. Real time information OM3 Test Bank Chapter 17 4 . Finished goods inventory d. Inventory d.ANS: A PTS: 1 6. Motion b. Based on forecast ANS: A PTS: 1 12. Maximize equipment effectiveness b. Six Sigma ANS: B PTS: 1 7. Foster continuous improvement efforts d. Toyota classified waste into seven major categories. Starting with a plan b. c. Setup time c. Which of the following "lean" ideas is false? a. Part waiting time d. General Motors supply chain is a good example of a push system. b. OM3 Test Bank Chapter 17 5 . Safety stock ANS: B PTS: 1 15. Southwest Airlines illustrates the application of "lean principles" when it a. b. d. Sales rate ANS: A PTS: 1 13. requires a change of ticket fee for missing a scheduled flight. c. Authorizes production b. Which one of the following statements is true concerning Lean Six Sigma? a. Lean principles focus on advanced statistical methods. Authorizes shipping to customers ANS: C PTS: 1 14. Reduce workforce c. assigns airplane seats. Lean principles have been developed over a sixty year plus period of time. Activities not adding value are a waste. Eliminate waste b. ANS: C PTS: 1 16. Which one of the following statements is true? a. Flexibility and responsive service are top priorities compared to low cost in an efficient supply chain. c. b. Dell Computers supply chain is a good example of push system. Lean principles include the 5Ss framework and practices.d. Principles of lean operating systems include all of the following except a. A withdrawal Kanban a. d. Increase speed and response d. Six Sigma and lean principles are not related they are separate bodies of knowledge. d. ANS: B PTS: 1 18. Postponement is the process of delaying orders from suppliers because it is very difficult to order from geographically dispersed businesses. Authorizes suppliers to produce c. Reduce cost ANS: B PTS: 1 19. The number of Kanban cards is dependent on all of the following except a. ANS: A PTS: 1 17. reduces airplane turnaround time at airport gates. serves all passengers in-flight dinners. Authorizes the transfer of an empty container d. Average daily demand rate b. A pull system produces waste. higher quality and lower costs. d.34 days. Dealer parking lot space will need to be increased. d. Accidents are a form of waste. Increased speed and response 3. and smooth. Producing goods early is a principle of lean. but raw materials and work-in-process inventories will increase. The daily demand is 800 units. the reorder point (r) in a fixed quantity inventory system. Overproduction is a form of waste. b. Improved quality OM3 Test Bank Chapter 17 6 . demand during the lead time only in a fixed quantity inventory system. 1. d. Each container has a combined waiting and processing time of 0. Lean operating systems have four basic principles. Ford Motor Company has decided to switch to a pull system of manufacturing and distribution for its vehicles. If the container size is 50 and efficiency (safety) factor is 9 percent. safety stock only in a fixed period inventory system.b. Elimination of waste 2. the order up-to-level (M) in a fixed period inventory system. A university publication printed with 100% post-consumer recycled fiber is an example of total productive maintenance practice. ANS: D PTS: 1 22. Which one of the following statements is true? a. c. c. ANS: B PTS: 1 21. 6 sets c. Inventory levels will increase. ANS: C PTS: 1 20. c. efficient flow of materials and information throughout the value chain to obtain faster customer response. ABC Manufacturing uses a Kanban system for a component. b. Which one of the following is most likely to occur? a. The heijunka system is a system of boxes much like in a mailroom set of boxes attached to a wall used to smooth production outputs. 7 sets d. Define lean enterprise and the four principles of lean operating systems. d. ANS: Lean enterprise refers to approaches that focus on the elimination of waste in all forms. Preventive maintenance is not a part of lean principles and practices. how many Kanban card sets should be authorized (round up)? a. c. Component parts and subassemblies will be replenished only when needed. the numerator of the formula K =[d(p + w)(1 + )]/C is analogous to a. ANS: A PTS: 1 SHORT ANSWER 1. 8 sets ANS: B PTS: 1 23. Finished goods inventory will decrease. 5 sets b. In a Kanban system. b. Motion . 3. PTS: 1 4. Single Minute Exchange of Die (SMED) refers to quick setup or changeover of tooling and fixtures in processes so that multiple products in smaller batches can be run on the same equipment. For example.Production defects are a result of not performing work correctly the first time. they make a batch of 52 instead of 50 in case there are rejects. Contrast batching with single-piece flow. if a machine fails or a part is defective or manufactured incorrectly.Inventory waste is the expense incurred to meet the requirements needed to maintain. Short setup times. Over-production . and the resulting excess inventory simply sits idle. Waiting time . PTS: 1 3. 6.Longer lead-times and higher work-in-progress results from allowing queues to build up between operations.Poor layout leads to the waste of time and effort spent in moving products around the factory. Production defects . 4. Transportation .Scrap that often results from poor product or process design exemplifies the traditional notion of waste. Reduced cost PTS: 1 2. thus achieving high flexibility and product variety. Explain the concept of Single Minute Exchange of Die (SMED). 5.For example. Over-production ties up production facilities. indicating that immediate action should be taken. a light might turn on or a buzzer might sound. and so on.4. ANS: The Toyotas Motor Company classified waste into the following seven major categories: 1. on the other hand. Discuss the seven major categories of waste as defined by Toyota. enable a manufacturer to have frequent changeovers and move toward single-piece flow. 7. Inventory .Motion waste is the result of inefficient workplace design. Reducing setup times also frees up capacity for other productive uses. speed of service. ANS: Long setup times waste manufacturing resources. Processing . 2. Some firms use electronic “scoreboards” to keep track of daily performance. quality levels. These scoreboards are located where everyone can see them and report key metrics such as volume. a company makes a batch of 100 when they only had orders for 50. PTS: 1 5. handle and store idle stock. OM3 Test Bank Chapter 17 7 . and the location of tools and materials. Many firms have cords that operators can pull that tell supervisors and other workers that a problem has occurred. ANS: Visual controls are indicators for operating activities that are placed in plain sight of all employees so that everyone can quickly and easily understand the status and performance of the work system. Explain the purpose of visual controls and give examples. or. to avoid an expensive setup cost. By running large batches. communication and organizational structures. seiton (set in order). seiso (shine). TPM has been described as the health care system for the operating system. this often builds up inventory that might not match market demand. PTS: 1 7. Explain the 5Ss. providing economies of scale. The goal of TPM is to prevent equipment failures and downtime -ideally. to do this economically requires the ability to change between products quickly and inexpensively. while Six Sigma is focused on effectiveness by reducing errors and defects.ANS: Batching is the process of producing large quantities of items as a group before being transferred to the next operation. setups and teardowns are reduced. TPM seeks to Maximize overall equipment effectiveness and eliminate unplanned downtime Create workers' "ownership" of the equipment by involving them in maintenance activities Foster continuous efforts to improve equipment operation through employee involvement activities PTS: 1 8. Standardize means to formalize procedures and practices to create consistency and ensure that all steps are performed correctly. However. maintenance problems such as oil leaks can be identified before they cause problems. Sort refers to ensuring that each item in a workplace is in its proper place or identified as unnecessary and removed. to have "zero accidents. PTS: 1 6. ANS: Lean production addresses visible problems in processes. Single-piece flow is the concept of ideally using batch sizes of one. How does Total Productive Maintenance (TPM) affect lean operating systems? ANS: Total Productive Maintenance (TPM) is focused on ensuring that operating systems will perform their intended function reliably. but it is also important because as a work area is cleaned. Sustain means to keep the process going through training. Six Sigma is more concerned with less visible problems such as variation in performance. However. Lean is focused on efficiency by reducing waste and improving process flow. OM3 Test Bank Chapter 17 8 . Discuss the differences between lean production and Six Sigma. zero defects and zero failures" in the entire life cycle of the operating system. Not only is this important for safety. Shine refers to a clean work area. particularly in highly dynamic markets. ANS: The 5Ss are derived from Japanese terms: seiri (sort). Set in order means to arrange materials and equipment so that they are easy to find and use. seiketsu (standardize) and shitsuke (sustain). The Kanban process is complete when the material handler for the customer process picks up a full container of parts and takes the production Kanban card off the container. employees at a given operation go to the source of required parts. process area used. 9. Parts and subassemblies are "pushed" through the operating system based on a pre-defined schedule that is independent of actual customer demand.Another difference is that lean tools are more intuitive and easier to apply by anybody in the workplace. resulting in minimal inventories and maximum responsiveness. PTS: 1 10. Describe how it helps execute a pull system. using a forecast of sales. As the process from which parts were withdrawn replenishes the items transferred out. Withdraw Kanbans trigger the movement of parts. etc. it draws on the output of its preceding process. Step 1: Step 2: Step 3: The withdraw Kanban authorizes the material handler to transfer empty containers to the storage area. leaving the empty container. The container holds a small lot-size of parts. Finished goods are made to coincide with the actual rate of demand. particularly in statistical analysis. description. which produces finished goods inventory in advance of customer demand. The other workstations in the process do not need to be scheduled because they get their production orders from the production Kanban that pulls parts through the supply process. quantity available. The gateway workstation must be scheduled to meet the sales rate and it pulls parts from all other workstations. Normally. and withdraw the units as they need them. Production Kanbans trigger the production of parts. ANS: Traditional factories use a push system. the material handler drops off a withdrawal Kanban and empty container when they pick up a full container of parts. quantity delivered. A material handler for the supply cycle places a production Kanban on the empty container and this authorizes the gateway workstation to produce parts. the gateway workstation and all other workstation may be idle. production quantity. etc. a pull system. The supply process returns a full container of parts to the storage area with the production Kanban attached. The material handler detaches the withdraw-ordering Kanban that was attached to the empty container and places the Kanban card in the storage area or on the Kanban receiving post. Define a Kanban. Compare and contrast a push system vs. just enough new parts are manufactured or procured to replace those withdrawn. ANS: A Kanban is a flag or a piece of paper that contains all relevant information for an order: part number. such as machining or subassembly. PTS: 1 PROBLEM OM3 Test Bank Chapter 17 9 . Without the authorization of the production Kanban. The Kanban system begins when the customer buys or uses the good and an empty container is created. In a pull system. while many Six Sigma tools require advanced training and expertise of specialists. Then. time of delivery. What is the number of containers currently in use? b. How many Kanbans are required? ANS: K = Average daily demand during lead time plus a safety stock/Number of units per container K = d(p + w)(1 + )/C d = 75 p+w=3 C=8 =2 K = d(p + w)(1 + )/C = 75(3)(1 + 2)/8 = 84.375 or rounded up to 85 PTS: 1 3.37 + 0. The company is interested in reducing the number of containers.37 days. filled with production.5) (1+.05)(1 + . A company is using Kanban containers. K = d(p + w)(1 + )/C = [(200) (. It takes . If the number of parts a container holds is increased to 24 parts.10 K = d(p + w)(1 + )/C = 900(0.05 p = 0. The Container size is 60 hinges and the safety factor ( ) is 10%. The demand for #321 is 75/day and they are built in groups of 8. The total process and wait time is 3 days.2)] / 20 = 6 containers b.93. How many Kanban card sets should be authorized? What is the maximum inventory of this hinge in the system? ANS: a.2)] / 24 = 5 containers OM3 Test Bank Chapter 17 10 . and a processing time of 0.1. Maximum inventory = K x C = 420 PTS: 1 2. how many containers are needed? c. There are two adjacent work centers. a downstream (using) and an upstream (producing) one. K = Average daily demand during lead time plus a safety stock/Number of units per container K = d(p + w)(1 + )/C d = 900 w = 0. a. If the company wants the number of containers (holding 20 parts each) to be 5.1)/60 = 6. and leaves again. The manager wants a safety factor () of 20%. a. Each container has a wait time of 0. K = d(p + w)(1 + )/C = [(200) (. what must the safety factor become? ANS: a. The manager wants an alpha () of 2 or 200%. A manufacturer of automobile engines is designing a new Kanban system for engine #321. Hinge Manufacturing Company employs a Kanban system for a component part.5 days for a container to make the entire cycle from the time it leaves the upstream center until it is returned. b.37 C = 60 = . The daily demand is 900 hinges.5) (1 +. rounded up to 7 b. The using work center has a production rate of 200 parts per day and each container holds 20 parts.05/day. What is the safety factor for the current operation? What is the maximum authorized inventory for this part? If the number of containers is reduced to one.25)] = . The average elapsed time for the entire cycle is currently . how many parts must it hold? c.25)]/[(250)(. between a downstream (using) and an upstream (producing) work center. K = [d(p + w) (l + )] / C = [(100)(. how many containers will be needed? ANS: a. The company is concerned with the safety factor for the operation and the size of the containers. KC = 2(25) = 50 c.12 and there are still 2 containers.40)(1 + . b. C = [d(p + w) (1 + )] / K = [(250) (. If the safety factor is changed to . each holding 50 parts. A manufacturing company is using a two-container Kanban system between a downstream (using) and an upstream (producing) work center. = [KC d(p + w)] / d(p + w) = [(5)(20) (200)(. how many parts must it hold? If the efficiency is changed to . The using work center can handle 250 jobs per day. C = [d(p + w) (l + )] / K = [(100)(. Each container holds 25 parts.25 days. = [KC d(p + w)] / d(p + w) = [(2)(50) (250)(.25) (1 + .60 b. A company is using a Kanban system with 2 containers.25 b. a.40)(1 + .40 days. If the company decides to use only one container. The using work center can handle 100 parts per day. The average elapsed time for the entire cycle is currently . how many parts must each container now hold? ANS: a. What is the efficiency rating of the current operation? b.40)] = .10)] / 44 = 1 container PTS: 1 OM3 Test Bank Chapter 17 11 .5)] / (200)(.25)] / 1 = 50 parts d. a.5) = .c. d.00 PTS: 1 4. The company is concerned about the efficiency of the operation.10 and the number of parts per container is increased to 44.25)(1 + .40)] /[(100)(. = [KC d(p + w)] / d(p + w) = [(2)(25) (100)(. C = [d(p + w) (1 + )]/K = [(250)(. c.6)] / 1 = 100 c.12)]/2 = 35 parts PTS: 1 5.