JIT JustInTime Production 982021 1 Introduction to JIT

JIT – Just-In-Time Production 9/8/2021 1

Introduction to JIT Overview of JIT n JIT is a pull production system Catch Phrase n 9/8/2021 “The right part in the right place at the right time” 2

History of JIT Taiichi Ohno of the Toyota Motor Corporation is often referred to as “The Father of JIT. ” The JIT management philosophy has been around since the 1950’s, which is when Ohno first started developing and practicing JIT concepts within the Toyota Corporation. Ohno titled his new methods of production the Toyota Production System (TPS), which has now become a synonymous term for JIT 9/8/2021 3

Toyota’s Lean Production House Goal: highest quality, lowest cost, shortest leadtime Jidoka Heijunka JIT 5 S Standardized Work Just in Time (JIT) – continuous flow, pull system, or kanban Kaizen Stability – Stable Manufacturing Processes, 100% Quality, Total Preventative Maintenance 9/8/2021 4

Synonyms for JIT Toyota Production System Stockless production Lean production Kanban system 9/8/2021 5

JIT Goal and Philosophies GOAL of JIT: Production control through waste elimination Philosophy of JIT n n n 9/8/2021 Elimination of waste Broad view of operations Simplicity Continuous improvement Visibility Flexibility 6

JIT Principles Simplification Cleanliness and organization Visibility Cycle timing Agility Variation reduction Measurement 9/8/2021 7

Elements of JIT Meet daily Discuss work practices Reduce buffer stock Modify machinery – reduced setup 9/8/2021 Reveal non-value added practices Involve the workforce: consultation instead of confrontation Expose problems 8

Benefits of JIT Better quality products Reduced scrap and rework Reduced cycle times Lower setup times Smoother production flow Cost savings 9/8/2021 Less inventory Higher productivity Most skilled workforce Reduced space requirements Higher work participation 9

Toyota’s Seven Wastes Producing defects Transportation Inventory Overproduction Waiting Time Processing Motion 9/8/2021 10

Canon’s Nine Wastes Work-in-process Defects Equipment Expense Indirect labor Planning Human resources Operations Startup 9/8/2021 11

The Five Why’s Ask “Why” five times to get to the source of waste and the cause of problems 1. 2. 3. 4. 5. 9/8/2021 Why did the machine stop? Overload and blown fuse Why the overload? Not lubricated Why not lubricated? Oil pump not pumping Why not pumping? Pump shaft worn out Why worn out? No screen, scrap was let in 12

Push vs. Pull Push System Material is pushed downstream and inventory builds regardless of resource availability n Strong emphasis on production first n Stock points and additional inventory can overflow with parts and raw materials n 9/8/2021 13

Traditional Push Production System Big purchase shipments w/ lower per unit shipping cost 9/8/2021 Big “pushes” Huge lot sizes of finished Lots of inventory “Push” material to goods to next stage warehouse or customers 14

Pull vs. Push Pull System The customer starts the production process by pulling production when it is needed n Material is moved to workstations as it is needed n Stock points are kept at a minimum n Waste is MINIMIZED n 9/8/2021 15

Pull Production System Smaller shipments w/ minimal / no inventory holding cost 9/8/2021 Smaller lots Faster setups Less inventory Goods are “pulled” by demand out of the plant 16

Necessary Conditions For Pull 1. 2. 3. 4. 5. 6. 7. 8. 9. Planning and Control Responsibility Producing to Meet Demand Reduce In-Process Inventories Preventative Maintenance Quality Assurance Setup Times Must be Small Linking of All Operations Production Plans and Schedules Must Be Uniform Develop Cooperative Attitudes and Teamwork 9/8/2021 17

Achieving Pull Production Pull System as Reorder Point (ROP) System D = demand (consumption rate) LT = lead time (elapsed time btwn order and replenishment P = production time C = conveyance time (time to convey order to upstream process, plus time to move materials to the downstream operation SS = safety stock (number of parts) 9/8/2021 18

Achieving Pull Production Standard-Sized Containers n If Q = the capacity of a standard container, then ROP as expressed in terms of the number of containers is K, or the maximum number of completely full containers in a buffer Container Size n 9/8/2021 Container should hold about 10% of the daily demand 19

Kanban card shows typical production quantity Derived from two-bin inventory system Maintains pull production system A production kanban authorized production A withdrawal kanban authorizes material handling 9/8/2021 20

Kanban Pre-Conditions Point of use inclusion (all parts on the assembly line) Level production There are four pre -conditions for the successful implementation of Kanban Quick Changeover procedures 9/8/2021 Stabilized processes 21

Kanban means “signboard” n 9/8/2021 Kanban is a signal used to communicate production cues in a pull production system 22

Sample Kanban Card Part No. : Description: From: Assembly 3 9/8/2021 6934 Servo motor Box capacity: Box type: Issue No. : 30 AF 06 To: Station D-7 23

Sample Kanban Card Market Address Kanban Number Line-Side Address <<Market_Address>><<Kanban_Number>> <<Line_Side_Address>> Part Number Route <<Part Number>> <<Route>> Bar Code Area Part Description <<Part Number>> Supplier Code <<Supplier Comment: 9/8/2021 Code >> Dock Code <<Dock Quantity Code>> Serial Number <<Quantity>> <<Comment>> 24

Conveyance Kanbans A conveyance kanban, or C-kanban, authorizes containers to move from an upstream, outbound buffer to a downstream, inbound buffer Kc = number of C-kanbans C = total time between when workers remove a C-kanban from a full container at the inbound buffer and when they remove a C-kanban from the next full container 9/8/2021 25

Production Kanbans P-kanban is used to authorize production parts to assemblies Kp = number of P-kanbans P = total time elapsed from when workers or mat’l handlers remove the P-kanban from a full container and post it at the outbound buffer until the time they remove the P-kanban from the next full container 9/8/2021 26

1 & 2 -Card Kanban Systems 1 -card systems use only C-kanbans 2 -card systems use both C-kanbans and Pkanbans 9/8/2021 27

DISCUSSION 9/8/2021 28