Download presentation
Published byDrake Beed Modified over 10 years ago
1
Operations and Supply Chain Management, 8th Edition
Chapter 16 Lean Systems Russell and Taylor Operations and Supply Chain Management, 8th Edition
2
Lecture Outline Basic Elements of Lean Production – Slide 4
Implementing Lean Systems – Slide 47 Lean Six Sigma – Slide 49 Value Stream Mapping – Slide 50 Lean and the Environment – Slide 54 Lean Services – Slide 56 © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
3
Learning Objectives Explain how the basic elements of lean eliminate waste, create flow and continuously improve operations Assess the benefits of lean, as well as the difficulties in implementing lean systems Explain how the complementary concepts of lean and six sigma work together for process improvement Construct and interpret a value stream map Create strategies for implementing lean in service industries Use lean concepts and techniques to enhance environmental initiatives © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
4
Basic Elements of Lean Production
Doing more with less inventory, fewer workers, less space Just-in-time (JIT) smoothing the flow of material to arrive just as it is needed “JIT” and “Lean Production” are used interchangeably Muda waste, anything other than that which adds value to product or service © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
5
Waste in Operations © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
6
Waste in Operations © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
7
Waste in Operations © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
8
Elements of Lean Production
Flexible resources Cellular layouts Pull system Kanbans Small lots Quick setups Uniform production levels Quality at the source Total productive maintenance Supplier networks © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
9
Flexible Resources Multifunctional workers
perform more than one job General-purpose machines perform several basic functions Cycle time time required for the worker to complete one pass through the operations assigned Takt time paces production to customer demand © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
10
Standard Operating Routine for a Worker
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
11
Cellular Layouts Manufacturing cells
comprised of dissimilar machines brought together to manufacture a family of parts Cycle time is adjusted to match takt time by changing worker paths © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
12
Cells With Worker Routes
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
13
Worker Routes Lengthen as Volume Decreases
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
14
Pull System Material is pulled through the system when needed
Reversal of traditional push system where material is pushed according to a schedule Forces cooperation Prevent over and underproduction While push systems rely on a predetermined schedule, pull systems rely on customer requests © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
15
Kanbans Card which indicates standard quantity of production
Derived from two-bin inventory system Maintain discipline of pull production Authorize production and movement of goods © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
16
Sample Kanban © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
17
Origin of Kanban © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
18
Types of Kanban Production kanban Withdrawal kanban Kanban square
authorizes production of goods Withdrawal kanban authorizes movement of goods Kanban square a marked area designated to hold items Signal kanban triangular kanban to signal production at the previous workstation Material kanban to order material in advance of a process Supplier kanban rotates between the factory and suppliers © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
19
Dual Kanban System © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
20
Other Kanbans © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
21
Other Kanbans © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
22
Determining Number of Kanbans
where N = number of kanbans or containers d = average demand over some time period L = lead time to replenish an order S = safety stock C = container size No. of Kanbans = average demand during lead time + safety stock container size N = dL + S C © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
23
Determining Number of Kanbans
d = 150 bottles per hour L = 30 minutes = 0.5 hours S = 0.10 (150 x 0.5) = 7.5 C = 25 bottles N = = dL + S C © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
24
Determining Number of Kanbans
d = 150 bottles per hour L = 30 minutes = 0.5 hours S = 0.10 (150 x 0.5) = 7.5 C = 25 bottles Round up to 4 (to allow some slack) or down to 3 (to force improvement) N = = = = 3.3 kanbans or containers dL + S C (150 x 0.5) + 7.5 25 © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
25
Small Lots Require less space and capital investment
Move processes closer together Make quality problems easier to detect Make processes more dependent on each other © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
26
Inventory Hides Problems
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
27
Less Inventory Exposes Problems
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
28
Components of Lead Time
Processing time Reduce number of items or improve efficiency Move time Reduce distances, simplify movements, standardize routings Waiting time Better scheduling, sufficient capacity Setup time Generally the biggest bottleneck © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
29
Quick Setups Internal setup External setup SMED Principles
Can be performed only when a process is stopped External setup Can be performed in advance SMED Principles Separate internal setup from external setup Convert internal setup to external setup Streamline all aspects of setup Perform setup activities in parallel or eliminate them entirely © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
30
Techniques for Reducing Setup Time
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
31
Uniform Production Levels
Result from smoothing production requirements on final assembly line Kanban systems can handle +/- 10% demand changes Reduce variability with more accurate forecasts Smooth demand across planning horizon Mixed-model assembly steadies component production © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
32
Mixed-Model Sequencing
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
33
Quality at the Source Visual control Poka-yokes Kaizen Jidoka Andons
makes problems visible Poka-yokes prevent defects from occurring Kaizen a system of continuous improvement; “change for the good of all” Jidoka authority to stop the production line Andons call lights that signal quality problems Under-capacity scheduling leaves time for planning, problem solving, and maintenance © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
34
Examples of Visual Control
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
35
Examples of Visual Control
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
36
Examples of Visual Control
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
37
5 Whys A key part in an effective Kaizen is finding the root cause of a problem and eliminating it A practice of asking “why?” repeatedly until the underlying cause is identified (usually requiring five questions) Simple, yet powerful technique for finding the root cause of a problem © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
38
Total Productive Maintenance (TPM)
Breakdown maintenance Repairs to make failed machine operational Preventive maintenance System of periodic inspection and maintenance to keep machines operating TPM combines preventive maintenance and total quality concepts © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
39
TPM Requirements Design products that can be easily produced on existing machines Design machines for easier operation, changeover, maintenance Train and retrain workers to operate machines Purchase machines that maximize productive potential Design preventive maintenance plan spanning life of machine © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
40
5S Workplace Scan 5S Scan Goal Eliminate or Correct Seiri (sort)
Seiton (set in order) Seisou (shine) 5S Scan Keep only what you need A place for everything and everything in its place Cleaning, and looking for ways to keep clean and organized Goal Unneeded equipment, tools, furniture; unneeded items on walls, bulletins; items blocking aisles or stacked in corners; unneeded inventory, supplies, parts; safety hazards Items not in their correct places; correct places not obvious; aisles, workstations, & equipment locations not indicated; items not put away immediately after use Floors, walls, stairs, equipment, & surfaces not clean; cleaning materials not easily accessible; lines, labels, signs broken or unclean; other cleaning problems Eliminate or Correct © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
41
5S Workplace Scan 5S Scan Goal Eliminate or Correct Seiketsu
(standardize) Shisuke (sustain) 5S Scan Maintaining and monitoring the first three categories Sticking to the rules Goal Necessary information not visible; standards not known; checklists missing; quantities and limits not easily recognizable; items can’t be located within 30 seconds Number of workers without 5S training; number of daily 5S inspections not performed; number of personal items not stored; number of times job aids not available or up-to-date Eliminate or Correct © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
42
Supplier Networks Long-term supplier contracts Synchronized production
Supplier certification Mixed loads and frequent deliveries Precise delivery schedules Standardized, sequenced delivery Locating in close proximity to the customer © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
43
Benefits of Lean Production
Reduced inventory Improved quality Lower costs Reduced space requirements Shorter lead time Increased productivity © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
44
Benefits of Lean Production
Greater flexibility Better relations with suppliers Simplified scheduling and control activities Increased capacity Better use of human resources More product variety © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
45
Implementing Lean Systems
Use lean production to finely tune an operating system Somewhat different in USA than Japan Lean production is still evolving Lean production is not for everyone © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
46
Drawbacks of Lean Production
Highly variable demand Large variety of low-volume products Custom engineered products Mass production parts Unexpected changes in demand or supply © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
47
Lean Six Sigma Lean and Six Sigma are natural partners for process improvement Lean Eliminates waste and creates flow More continuous improvement Six Sigma Reduces variability and enhances process capabilities Requires breakthrough improvements © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
48
Value Stream Mapping (VSM)
A tool for analyzing process flows and eliminating waste Specialized icons related to lean production material and information flows “aha” Kaizen bursts © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
49
VSM Shapes © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
50
VSM for Milling & Welding
© 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
51
VSM for Emergency Room © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
52
Lean and the Environment
Identify environmental waste along with other forms These can indicate poor process design Reduce costs of material energy regulatory compliance Reduce worker health and safety risks © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
53
US EPA Recommendations
Commit to eliminate environmental waste Involve staff with environmental expertise in planning for & implementing lean events Find & drive out environmental waste in specific processes by using lean tools Empower & enable workers to eliminate environmental waste in their work areas Use environmental, health & safety icons in VSM © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
54
Lean Services Basic elements of lean production apply equally to services Most prevalent applications lean retailing lean banking lean health care supply chain © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
55
Leaning the Supply Chain
“pulling” a smooth flow of material through a series of suppliers to support frequent replenishment orders and changes in customer demand Firms need to share information and coordinate demand forecasts, production planning, and inventory replenishment with suppliers and supplier’s suppliers throughout supply chain © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
56
Leaning the Supply Chain
Pull a smooth flow of material through the system Build a highly collaborative business environment Adopt the technology to support your system Consider “near shoring” © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
57
Copyright 2014 John Wiley & Sons, Inc. All rights reserved
Copyright 2014 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permission Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information herein. © 2014 John Wiley & Sons, Inc. - Russell and Taylor 8e
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.