ISQA 459 Mellie Pullman 1

 JIT can be defined as an integrated set of activities designed to achieve high-volume production using minimal inventories (raw materials, work in process, and finished goods).  JIT also involves the elimination of waste in production effort.  JIT also involves the timing of production resources (e.g., parts arrive at the next workstation “just in time”). 2

 Elimination of waste  Efforts concentrated on shop floor  Respect for people  Quality improvement focus 3

(1) Waste from overproduction (2) Waste of waiting time (3) Transportation waste (4) Inventory waste (5) Processing waste (6) Waste of motion (7) Waste from product defects 4

5 Customers Sub Fab Vendor Final Assembly

6 Final Assembly Coordination System Integration

7 A B C A C B Sporadic and Infrequent Deliveries from Individual Suppliers

8 A B C ABC Regular and Frequent Deliveries from Many Suppliers

 Using Departmental Specialization for plant layout can cause a lot of unnecessary material movement. 9 Saw LathePress Grinder Lathe Saw Press Heat Treat Grinder

 Revising by using Group Technology Cells can reduce movement and improve product flow. 10 Press Lathe Grinder A 2 B Saw Heat Treat LatheSaw Lathe Press Lathe 1

11 Not uniformJan. UnitsFeb. UnitsMar. UnitsTotal 1,2003,5004,3009,000 UniformJan. UnitsFeb. UnitsMar. UnitsTotal 3,0003,0003,0009,000 Suppose we operate a production plant that produces a single product. The schedule of production for this product could be accomplished using either of the two plant loading schedules below. How does the uniform loading help save labor costs? or

 Company produces three products with a mixed model assembly line.  Operates 16 hours per day for 250 days/yr.  Determine the mixed model MPS for a daily batch.  Determine minimum batch MPS and the mix schedule for a day. ProductsForecasts (year) 120, ,000 35,000 12

#1#2#3 Year Forecast Daily Batchdivide by Hourly Batchdivide by Minimum Batch MPS For every unit of #3 (minimum batch), we need twice as many #2 and 4 times As many #1 so for minimum batch: Produce during each day produce #1,1,1,1,2,2,3 - repeated 20 times

 Company produces four products with a mixed model assembly line.  Operates 8hours per day for 250 days/yr.  Determine the mixed model MPS for a daily and hourly batch.  Determine mix schedule for a day. ProductsForecasts (year) I500 II1500 III4500 IV

15 Management philosophy “Pull” system though the plant WHAT IT IS Employee participation Industrial engineering/basics Continuing improvement Total quality control Small lot sizes WHAT IT REQUIRES Attacks waste Exposes problems and bottlenecks Achieves streamlined production WHAT IT DOES Stable environment WHAT IT ASSUMES

16 Work in process queues (banks) Change orders Engineering design redundancies Vendor delinquencies Scrap Design backlogs Machine downtime Decision backlogs Inspection backlogs Paperwork backlog Example: By identifying defective items from a vendor early in the production process the downstream work is saved. Example: By identifying defective work by employees upstream, the downstream work is saved.

17 Storage Part A Machine Center Assembly Line Material Flow Card (signal) Flow Withdrawal kanban Production kanban

 Setting up a kanban system requires determining the number of kanbans (or containers) needed.  Each container represents the minimum production lot size.  An accurate estimate of the lead time required to produce a container is key to determining how many kanbans are required. 18

19 k = Number of kanban card sets (a set is a card) d = Average number of units demanded over some time period L = lead time to replenish an order (same units of time as demand) S = Safety stock expressed as a percentage of demand during lead time C = Container size

 A switch assembly is assembled in batches of 4 units from an “upstream” assembly area and delivered in a special container to a “downstream” control-panel assembly operation.  The control-panel assembly area requires 5 switch assemblies per hour.  The switch assembly area can produce a container of switch assemblies in 2 hours.  Safety stock has been set at 10% of needed inventory. 20

21 Always round up!

 Link operations  Balance workstation capacities  Re-layout for flow  Emphasize preventive maintenance  Reduce lot sizes  Reduce setup/changeover time 22

 Standard product configuration  Standardize and reduce number of parts  Process design with product design  Quality expectations 23

 Level payrolls  Cooperative employee unions  Subcontractor networks  Inverted pyramid management style  Small group involvement activities 24

 Worker responsibility  Measure SQC  Enforce compliance  Fail-safe (Poke-yoke) methods  Automatic inspection 25

 Damaged parts  Missing parts  Reversed parts  Wrong parts  Wrong size or shape  Wrong chemical properties  Wrong physical properties  Wrong item shipped  Wrong label  Wrong package  Damaged finished product  Omitting a part  Omitting a process  Performing a process incorrectly  Performing a process on the wrong part  Performing a process in improper environmental conditions  Performing the wrong process  Setting up equipment incorrectly  Setting up a work piece incorrectly  Adjusting equipment incorrectly  Tooling set up incorrectly  Tooling adjusted incorrectly  Installing wrong part  Installing part incorrectly 26 DEFECTSMISTAKES

 Reduce lead times  Frequent deliveries  Project usage requirements  Quality expectations 27

 Look for other areas where inventory hides  Stores  Transit  Carousels  Conveyors 28

29 MRP is a planning system that does not do detailed shop floor schedulingMRP is a planning system that does not do detailed shop floor scheduling MRP requires fixed lead times which might actually vary with batch sizeMRP requires fixed lead times which might actually vary with batch size JIT excels at rapidly moving small batches of material through the systemJIT excels at rapidly moving small batches of material through the system

30 1.MRP “buckets” are reduced to daily or hourly The most common planning period (time bucket) for MRP systems is weeklyThe most common planning period (time bucket) for MRP systems is weekly 2.Planned receipts are used internally to sequence production 3.Inventory is moved through the plant on a JIT basis 4.Completed products are moved to finished goods inventory which reduces required quantities for subsequent planned orders Back flushing based on the BOM is used to deduct inventory that was used in production Back flushing based on the BOM is used to deduct inventory that was used in production

31 Used in repetitive operationsUsed in repetitive operations MRP plans are executed using JIT techniques based on “pull” principlesMRP plans are executed using JIT techniques based on “pull” principles Flows are carefully balanced with small lot sizesFlows are carefully balanced with small lot sizes

32 Items used by many products are held in a common area often called a supermarketItems used by many products are held in a common area often called a supermarket Items are withdrawn as neededItems are withdrawn as needed Inventory is maintained using JIT systems and proceduresInventory is maintained using JIT systems and procedures Common items are not planned by the MRP systemCommon items are not planned by the MRP system