Pull Systems: Overview, Challenges and Success Factors

Transcription

1 Pull Systems: Overview, Challenges and Success Factors Mike Osterling Session Objectives Cover the most common types of pull systems See some examples of application Discuss implementation issues Cover common factors of success 2 1

2 Principles of Lean Thinking 1. Specify value from the external customer s perspective 2. Identify and understand the value stream 3. Make value creating steps flow 4. Pull Flow at the pull of the customer Pull where flow isn t possible 5. Pursue perfection Lean Thinking, Womack & Jones 3 Traditional MRP Execution Supplier POs MRP Execution Forecast & Orders Production Schedule Customer Process 1 Process 2 Process 3 Process 4 Why is this referred to as push? 4 2

3 MRP A Great Execution Tool, if 100% accurate bills of materials Accurate transactions (receipts, issues, returns). Accurate counts: WIP, finished goods and parts Accurate forecast: volume, timing and mix No variation in actual usage versus planned usage No unplanned usage (engineers, service ) No lost parts or WIP Accurate scrap rates. Scrap reporting is 100% accurate Accurate lead times Schedule priorities don t change Open order status is perfect Pull Systems Definition A method of production control in which downstream consumption triggers replenishment. I used some, you now have permission to replace. 6 3

4 Purpose of Pull Systems It s the schedule Self control to manage overproduction Simplified scheduling process (less demand on planning & scheduling) Rapid response to changes in demand Visualize Expectations / needs Performance Problems 7 Types of Pull Systems One-piece flow Kanban Pulling specific part numbers Min / max; re-order point Vendor managed inventory (VMI) FIFO Lanes Pulling capacity (the next job) Other (construction, office, software ) 8 4

5 Kanban Signal Communicates: What to produce Where it is made How much to produce When to produce it Who the customer is 9 Kanban Purchased Parts 10 5

6 Multi card Kanban System Fixed quantity per kanban Adjust number of cards as demand changes (Relatively) easy to adjust when demand changes 11 Visual Kanban (no cards) - Subassemblies FIFO 12 6

7 Vendor Managed Inventory (VMI) Vendor: Sets up, reorders, delivers, restocks 13 Pull Systems FIFO Lane: Pulling the next job; pulling capacity 14 7

8 FIFO Lanes Multiple Suppliers for Single Process 15 Pull in the Office 16 8

9 Breakout Activity 2 or 3 people (at least one person with pull in place) 1. For those who work in an operation with pull systems in place: which form of pull is it (excluding one-piece flow)? 2. Pick one identify who sends what signal to who? Type of Pull System Kanban Min/Max; ROP Vendor Managed Inventory FIFO Lane 5 minutes Sends Signal to produce Receives signal to produce 17 Common Problems Timing (often late, or come in wrong sequence, or unclear priorities) Quantity (not enough, or too much, inventory) Missed signal (didn t see it / didn t pull card) Lost signal (where s the card?)? 18 9

10 Breakout Activity 2 or 3 people (at least one person with pull in place) Focus on one of your pull systems What are the top one or two problems you are having with execution? (e.g. lost cards, late receipts, missed signals, not enough / too much?) 5 minutes 19 Before you Fix it. Make sure you understand root cause! 5 Why & Cause-Effect Diagrams (aka: fishbone or Ishikawa) Facilitates brainstorming of potential causes of a problem ( undesired effect ) Start with categories of causes. Decreases chance that overlook a cause Doesn t show how much each cause contributes, if at all, to the problem Doesn t provide solutions 20 10

11 Cause-Effect Diagram Categories Undesired Effect Potential Causes 21 Root Cause Analysis Categories The Six Ms ( man ) ( mother nature ) 22 11

12 Breakout Activity 2 or 3 people (same groups) Focusing on one of the two top challenges you have with your pull system, start creating a cause-effect (fishbone) diagram The head of the fish is the bad thing (e.g. lost kanban cards, out of inventory,, etc. Categories - 6 M (or other) Man, machine, materials, method, metrics, mother nature 10 minutes 23 After the Fishbone Narrow down the causes to the significant few Design countermeasures (improvements) to address the significant few 24 12

13 Kanban (Fixing the Bin ) 25 Kanban Cart (Visualizing Shortages) 26 13

14 Pull Systems Kanban Scheduling Board (Visualizing the Schedule and Priorities) 27 a.k.a. Heijunka Board / (Load Leveling) Scheduling Board for Signal Kanban (Visualizing the Schedule, Problems & Priorities) 28 14

15 Visual Status & Prioritization 29 Visual Status & Prioritization 30 15

16 Automation 31 FIFO Lanes Multiple Suppliers & Customers Output Input 32 16

17 Pull Systems FIFO Lane with Simple Visual Aids 33 Pull on Complex Projects Pull system for fab and field work more flexible, less rework, balanced demand 17

18 Keys to Success Start with the purpose (what problem are you trying to solve) Don t copy what the other guys are doing adapt Pilot & experiment start small Early engagement of the frontlines; and train (but not too soon) Standardize, document, and change There will be problems! Measure, monitor and perform root-cause analysis 35 Resources Kanban for the Supply Chain, Cimorelli Kanban Made Simple, Gross & McInnis Kanban for the Shop Floor, Productivity Press Implementing a Mixed Model Kanban System: The Lean Replenishment Technique for Pull Production, Vatalaro Video: Kanban Systems, Society of Manufacturing Engineers 36 18

19 Thank You! Questions? Mike Osterling (619)