JIT Lean Production Part 2

Learning Objective 13-4 1) A two-card kanban system is a planning tool that links production and movement of units at two work centers. Answer: FALSE 2) The cards employed in a two-card kanban system are the production card and the move card. Answer: TRUE 3) A pull system is a production system in which actual downstream demand sets off a chain of events that pull material through various steps in the production process. Answer: TRUE 4) The forecast for next month is 200 units so the manufacturer gathers materials for this anticipated level of production activity. This is an example of pull production. Answer: FALSE 5) The greater the demand, the more kanbans are needed. Answer: TRUE 6) An increase in the safety factor results in an increase in the amount of inventory in a kanban system. Answer: TRUE 7) In the kanban formula, the letter T represents the time it takes to empty a box of parts through building product. Answer: FALSE 8) For a kanban system to work properly, demand rates must be relatively stable, and interruptions must be minimized. Answer: TRUE 9) Some companies have found it beneficial to combine the planning capabilities of kanban with the control capabilities of MRP. Answer: FALSE 10) A kanban can be: A) a container. B) a card. C) a visual cue. D) All of these can be kanbans. Answer: D 11) In a two-card kanban system: A) the production card signals when a move card should be moved to the next process step. B) the move card signals when a container of parts should be produced. C) the production card signals when a container that held parts should be returned to inventory. D) the move card signals when a container of parts should move to the next process step. Answer: D 12) In a two-card kanban system: A) each box of finished goods has a move card so it can be sent to the next step. B) each box of raw material has a production card so it can be made into finished goods. C) a downstream station pulls finished material out of a production area. D) demand for more raw materials pushes finished goods to the finished goods area. Answer: C 13) In a single-card kanban system: A) the single card is the production card. B) the empty container serves as the production card. C) the single card is the move signal. D) None of the above is correct in a single-card system. Answer: A 14) Liversuch Industries uses a kanban system to manage production of the J-15 subassembly. They have an hourly demand for 250 units and use containers that can hold 50 units each. It takes 90 minutes to fill and move a container of parts to the right place on the J-15 line that is currently rated at a 20% safety factor. How many production cards are needed? A) 540 B) 100 C) 9 D) 1.5 Answer: C 15) Livermore Industries uses a kanban system to manage production of the KR-9 subassembly. In a ten-hour day, they use 1500 units and use containers that can hold 50 units each. It takes 45 minutes to fill and move a container of parts to the right place on the KR-9 line that is currently rated at a 15% safety factor. How many production cards are needed? A) 3 B) 26 C) 82 D) 155 Answer: A 16) Livernonions Industries uses a kanban system to manage production of the BR-549 subassembly. In an eight-hour day, they use 900 units and use containers that can hold 30 units each. It takes 120 minutes to fill and move a container of parts to the right place on the BR-549 line that is currently rated at a 15% safety factor. How many production hours of inventory are needed? A) 18.4 B) 7.6 C) 4.3 D) 2.4 Answer: D 17) Olivia has had enough of the theoretical equations and rejects the higher math needed to calculate the number of kanbans for her system. One approach that some organizations take in lieu of the kanban equation is to: A) start with one kanban and operate as fast as they can with the one, before adding more kanbans to bring them up to speed. B) start with too many kanbans and gradually remove them until a problem arises. C) fully load their system with inventory and produce until they cannot build product. D) eliminate all inventory from the system and add material and parts until they can fill a customer order. Answer: B 18) Consider the adjacent work stations in this two card Kanban system. There is a move card located: A) in box A. B) in box B. C) both in box A and box C. D) in box C. Answer: C 19) Consider the adjacent work stations in this two card Kanban system. There is a production card located: A) in box A. B) in box B. C) at work center 1 and work center 2. D) in box C. Answer: B 20) Consider the adjacent work stations in this two card Kanban system. There is a production card located in the box labeled Outgoing Parts B. Work Center 3 pulls the parts from Work Center 2. Where does the production card go? A) The production card remains in the same box. B) The production card is placed at Work Center 3. C) The production card is placed at Work Center 2. D) The production card is placed in the box labeled Incoming Parts A. Answer: C 21) Consider the adjacent work stations in this two card Kanban system. Work Center 3 has just pulled the Incoming Parts C box to their work station. What happens to the cards in the Incoming Parts C box and at the work station? A) The move card at their station goes in the Incoming Parts C box and the production card is pulled from the Incoming Parts C box to signal the worker at Work Center 2 that there is a need to produce material. B) The production card at the station is passed back to Work Center 2 as a signal to produce more material and the move card is left at Work Center 3 to signal that they are ready to accept materials when they are complete at Work Center 2. C) The move card at their station goes in the box they will send downstream to Work Center 4 and the production card is placed at the Work Center 3 station while they are working on this batch of material. D) The production card at their station goes in the Incoming Parts C box and the move card is pulled from the Incoming Parts C box to signal the worker at Work Center 2 that there is a need to move material. Answer: D 22) Consider the adjacent work stations in this two card Kanban system. Work Center 3 has just pulled the Incoming Parts C box to their work station. Which of these statements is best? A) The move card will move backward from Work Center 3 to Work Center 2. B) The production card will move backward from Work Center 3 to Work Center 2. C) The move card will move forward from Work Center 3 to Work Center 4. D) Despite its name, the move card doesn't actually move from one station to the next, it will simply reside at Work Center 3 until the next box is finished. Answer: A 23) Consider the adjacent work stations in this two card Kanban system. Work Center 3 has just pulled the Incoming Parts C box to their work station. Plant manager Taichi Ohno grabs the microphone for the company PA system and announces that effective immediately, the company will switch to a one card system. Which of these actions is appropriate? A) The production card will be discarded and the empty container will function as a production signal. B) The move card will be discarded and the empty container will function as a move signal. C) Both the move and production cards will be discarded in favor of a combined move/production card. D) The production card will be discarded as production will be implied and the move cards will signal when items are needed downstream. Answer: B 24) Which of the following statements regarding supply chain synchronization using kanbans is BEST? A) An interruption in the flow of goods within a supplier's assembly operations will have no effect on final assembly downstream in the supply chain. B) For the system to work properly, demand rates must be relatively stable and interruptions must be minimized. C) If final assembly demand doubles, there is no need to change kanbans at each of the suppliers. D) Final assembly demand may rise or fall, but the sum of the kanbans among all suppliers in the supply chain will remain constant. Answer: B 25) When using MRP and kanban together: A) the control capabilities of MRP are used instead of those from kanban. B) the planning capabilities of kanban are used instead of those from MRP. C) the demand rate should be variable in order to derive the greatest benefit from the MRP portion of the system. D) the number of kanbans is recalculated from the MRP system's order changes throughout the horizon. Answer: D 26) A(n) ________ is a production control approach that uses containers, cards, or visual cues to control production and movement of goods throughout the supply chain. Answer: kanban system 27) Under two-card kanban system rules, each box of raw material must have a(n) ________, while each box of finished goods must have a(n) ________. Answer: move card; production card 28) A manufacturer waits to produce until they have an order from a customer. This type of production system is called ________. Answer: pull production 29) The number of kanbans in a production system is inversely related to the ________. Answer: container size 30) Companies that use MRP and kanban together use the ________ of MRP and the ________ of kanban. Answer: planning capabilities; control capabilities 31) Describe the movements of parts and kanbans in a two-card kanban system. Answer: A two-card kanban system has move cards in boxes of raw materials and production cards in boxes of finished goods. When a box of finished goods is pulled by a downstream position (by either a customer or another work center) the production card is removed from the box and placed at the upstream position, thus triggering the need to produce more parts at this position. To do so, the worker at this center must obtain more raw materials, so they pull a box of parts from the upstream position. As they pull this box of parts, they remove the card and place it in a conspicuous location at the upstream position. This serves as the order to fill that box with more raw materials. Once the box is filled with raw materials, the move card is put back in the box, ready for another cycle. The finished goods container works the same way; once the goods are finished, the production card is replaced and ready for the next iteration. 32) Two modules are used to feed the final assembly station on an assembly line. The final assembly station must produce 250 units in an eight-hour day. Each finished unit needs two module A's and 3 module B's. The factory uses a standard sized container that can hold 25 module A's or 35 module B's. It takes 2 hours to fill and move a container of module A's, but only 90 minutes to fill and move a container of module B's. If both module assembly processes have safety factors of 15%, how many containers should be used for each? How many hours of demand will this satisfy? Answer: The number of containers is governed by this equation. y= = 5.75 → 6 containers yA = = 4.62 → 5 containers yB = Due to rounding up, there is more inventory in the system than necessary and this will support more hours of production: Hours = = Module A = = = 0.3 days = 2.4 hours Module B = = = 0.23 days = 1.87 hours 33) What are the consequences of unstable demand and interrupted flows on a supply chain managed with a lean philosophy? Answer: Lean requires that demand be relatively stable and that flows be relatively smooth. If demand rates are unstable and high, then a downstream station might exhaust all of the inventory in their system and be starved for inventory if upstream stations cannot respond quickly enough. If flow is interrupted due to an unforeseen emergency, quality issues, etc., the downstream work station may grind to a halt while issues are worked out at the point of difficulty. 34) Use this material requirements planning record to explain how kanbans and MRP can be used together. This plant operates on a 40-hour week, and uses a 10% safety factor on a container size of 20 units with a half-day turnaround time on a container. What features of each system should be used and for what purposes? Week Gross Requirement Scheduled Receipts Projected Ending Inventory Net Requirements Planned Receipts Planned Orders 1 900 0 0 900 900 900 2 1000 0 0 1000 1000 1000 3 1100 0 0 1100 1100 1100 Answer: Companies that use both MRP and kanbans use the planning features of MRP and the control features of kanbans. This plant is adhering to the lean philosophy by making exactly what it needs each week with no anticipated ending inventory. As net requirements increase from week to week, the plant manager will have to increase the number of kanbans in the system according to the following calculations: y= y1 = = 4.95 → 5 containers y2 = = 5.5 → 6 containers y3 = = 6.05 → 7 containers