Energy Savings through Lean Thinking. Learning to See through Value Stream Mapping

Transcription

1 Learning to See through Value Stream Mapping

2 Value Stream Mapping Continuous Improvement Teams Pull/Kanban Cellular/Flow Changeover Reduction Batch Reduction Visual Control Supermarkets Quality 5S Standard Work Plant Layout TPM Value Stream Mapping

3 Rip-Chop-Mould (RCM) Operation

4 Rough Mill Moulding Department Edge-glued Panel WIP 1 Rip Saw Moulder To Shipping Chop Saw WIP Ripped Panels 3 4 WIP Crosscut Panels

5 Discussion Flow Diagram, RCM Process What waste do you see? What waste is not readily shown? What would you need to identify other forms of waste that doesn t add value to the product?

6 Definition of Waste waste is anything that, from the perspective of the customer, adds cost to a product or service but does not add value

7 Value Stream Mapping

8 Think About Value Stream Your Focus Total Value Stream Suppliers Your Plant Customers

9 Value Stream Mapping Help visualize flow in the whole system Sources of waste Common language Linkage between information and material flows Forms basis for implementation plan and prioritization

10 What Is Your Value Stream?

11 Important Lean Measures Cycle Time Value Added Time Lead Time

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14 Rip-Chop-Mould (RCM) Operation

15 Customer Requirements 15,000 drawer fronts per month Shipments are made 1 time a week by truck Customer allowed to increase order by 20% within 2 days of ship date

16 Work Time 20 days per month (late orders/expediting can result in extra days) One 8-hour shift operation in all production departments Two 10-minute breaks and 30- minute lunch break

17 Production Control MRP based system generates weekly departmental schedules, which are updated daily Weekly orders from customers Monthly forecast to suppliers Weekly lumber orders shipped bi-weekly Look and See used to update build schedule & parts requirements daily Expediting and overtime is used to meet demand when things go wrong

18 Ripping 2 operators Cycle time: 5 s Observed WIP inventory: 250 panels ( 1000 drawer fronts or 1.3 days) 375 ripped panels ( 750 drawer fronts or 1 day)

19 Chopping 1 operator Cycle time: 10 s Observed WIP inventory: 750 drawer front parts at out-feed

20 Moulding 2 operators Fletcher profiler that profiles all 4 sides Cycle time: 15 s Changeover time: 30 minutes Observed F/G inventory: 10,000 profiled drawer fronts

21 Monthly Forecast Energy Savings through Production Control MRP Weekly Orders Supplier Weekly Orders Daily Schedules Customer 15,000 Monthly 2X Weekly 1X Weekly I Ripping I Chopping I Moulding I 10,000 C/T=5s C/T=10s C/T=15s C/O=30m 1.3 d 1 d 1 d 5 S 10 S 15 S 13.3 d L/T = 16.7 d V/A = 30 S

22 Current State Summary For drawer front value stream: 30 s Value Added 16.7 days Lead Time 0.002% of the time is value added So how would you improve?

23 Root Causes of Waste Value Added Non- Value Added Non-Value Added 1. Overproduction 2. Defects 3. Unnecessary inventory 4. Inappropriate processing 5. Excessive transportation 6. Waiting 7. Unnecessary motion

24 Analysis Overproduction MRP scheduling based on forecast Large batch size 200+ Actual demand is hidden in information system

25 Analysis Defects First pass error-free rate < 85% Customer quality specifications are hidden in information system U pright D efect P areto C hart D efect P ercentage C orner C hip D rying Problem s U nsound W ood H um an M achine C ontrol H um an H andling W ane P rofile T ear-out O riginal Size Issue

26 Analysis Unnecessary Inventory Large finished goods inventory (2+ weeks) Some inventory is low demand or obsolete

27 Analysis Inappropriate Processing Large batch size 200+ Long/cluttered distances between machines (800 ft) Ineffective use of space (1100 ft 2 used just to store WIP) No standard work

28 Analysis Excessive Transportation Total travel distance from start to finish is 800 ft Large batches require forklift handling Cluttered, time-consuming, & unsafe transportation routes

29 Analysis Waiting Operators wait for forklifts to bring raw materials Operators wait for forklifts to remove processed materials Operators wait for machines to complete their cycles

30 Analysis Unnecessary Motion Walking around machines Bending and stretching to stack, unstack, and handle materials

31 Energy Use Hidden in Waste Energy Savings through Waste Type Overproduction Defects Unnecessary Inventory Inappropriate Processing Transportation Waiting Unnecessary Motion Energy Use Energy consumed operating equipment to make unnecessary products Energy used in making defective products More energy used for rework and repair efforts Energy used to heat, cool, light, and manage inventory storage and warehousing space Energy consumed in operating equipment related to unnecessary processing Use of not properly maintained equipment results in more energy use per unit of production Energy used for excessive transport Energy used to heat, cool, light, and manage larger spaces required for more transport capacity Energy used to heat, cool, light, and manage while down Use of less productive workforce results in more energy use per unit of production

32 Continuous Improvement Problem solving technique to improve processes Achieve smooth, level production Minimize waste Achieve standard work procedures Safety, quality, etc. Not just one time, it is continuous!

33 Monthly Forecast Energy Savings through Production Control MRP Weekly Orders Supplier Weekly Orders Daily Schedules Customer 15,000 Monthly 2X Weekly 1X Weekly I Ripping I Chopping I Moulding I 10,000 C/T=5s C/T=10s C/T=15s C/O=30m 1.3 d 1 d 1 d 5 S 10 S 15 S 13.3 d L/T = 16.7 d V/A = 30 S

34 Value Stream Map (RCM) Lead Time = 16.7 days Value added = 30 s How do we reduce Lead Time?

35 Where to Reduce Waste?

36 Future State Value Stream First iteration should take product design, process technology, and current plant resources as given and seek to remove as quickly as possible all sources of waste not caused by these features

37 Steps in Future State Produce to takt time Develop continuous flow Use supermarkets where continuous flow not possible Send production schedule to one process Distribute different production work evenly Release small consistent increments of work

38 Steps in Future State Produce to takt time

39 Overproduction

40 Takt Time Available working time/shift = 480 min - 50 min = 430 min = 25,800 s Target demand/shift = 17,200 pieces / 20 days = 860 pieces Takt time = 25,800/860 = 30 s

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42 Steps in Future State Produce to takt time Develop continuous flow

43 Notes Minimum theoretical lead time through Rip, Chop, and Mould is 30 seconds. Production control system didn t really think about takt time, through tradition based on some experience long ago, a weekly schedule is given to each machine.

44 Continuous Flow? takt time 30 s Current Operator Balance 5s R 10s C 15s M

45 If Continuous Is Practical - takt time 30 s Cycle time after a cellular redesign M C Total cycle time = 30 s R

46 Manufacturing Cell R C M

47 Replace 3 Process With Cell RCM process M C R Takt = 30 s C/T = 30 s

48 RCM Cell

49 Steps in Future State Produce to takt time Develop continuous flow Use supermarkets where continuous flow not possible

50 Smoothing Variations

51 #3 - Supermarket Systems

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54 R/M Supermarket F/G Supermarket RCM Cell

55 Steps in Future State Produce to takt time Develop continuous flow Use supermarkets where continuous flow not possible Send production schedule to one process Distribute different production work evenly Release small consistent increments of work

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57 Kanban Cards

58 Every Part Every Day ~10-15%

59 R/M Supermarket F/G Supermarket RCM Cell C/O = 10 min. C/O Reduction

60 Kaizen Definition RCM Cell Roughly translates as Good Change Team event One intense week of focused improvement Lean Training first day Eight to ten team members 50%+ improvement expected

61 RCM Cell

62 Exercise A continuous improvement event to create a Rip-Chop-Mould cell (see Rip-Chop-Mould Improvement Exercise) RCM Cell

63 What is the work? Step Time (seconds) Work Element Work Category 1 1 Get raw material (RM) Rip 3 Process material at Rip Saw 2 1 Place material on pallet 3 60 Forklift to Ripped WIP area 4 60 Forklift to Chop Saw 5 2 Get material from pallet Chop 6 Process material at Chop Saw 6 2 Place material on Pallet 7 60 Forklift to Ripped/Chopped WIP area 8 60 Forklift to Moulder 9 2 Get material from pallet 10 1 Load material into moulder Mould 6 Wait for Moulding process material at Moulder 11 4 Inspect finished part 12 2 Place part in finished goods bin

64 Machining needs TT 30 Waste Necessary Value Added rip Mould Chop Rip Chop Mould Step #10

65 Current Operator Balance TT Waste Necessary Value Added rip 1 2 rip 6 Chop 5 Wait Mould 10 9 R1 R2 C1 M1 M Wait Mould

66 Guidelines No walking No batching No out-of-cycle work No waiting for machines No unloading machine if simple auto-unload possible (gravity is free!)

67 Goals Step Time (seconds) Work Element Work Category 1 1 Get raw material (RM) Rip 3 Process material at Rip Saw 2 1 Place material on pallet 3 60 Forklift to Ripped WIP area 4 60 Forklift to Chop Saw 5 2 Get material from pallet Chop 6 Process material at Chop Saw 6 2 Place material on Pallet 7 60 Forklift to Ripped/Chopped WIP area 8 60 Forklift to Moulder 9 2 Get material from pallet 10 1 Load material into moulder Mould 6 Wait for Moulding process material at Moulder 11 4 Inspect finished part 12 2 Place part in finished goods bin

68 Proposed Operator Balance TT Waste Incidental Value Added rip 1 10 Chop rip Op. 1 Op. 2

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72 Can work be balanced? Op. 1 gets material (1) while Op. 2 loads Moulder (10) Op. 1 and 2 Rip Op. 1 inspects (11) while Op. 2 Chops Op. 1 stacks (12) while Op. finishes Chop Repeat cycle Rip 2 Chop Mould 10

73 Proposed Operator Balance TT Waste Incidental Value Added rip 1 10 Chop rip Op. 1 Op. 2

74 Measure Before After Improve Team Productivity Labor Min/Drw % Lead Time Days % WIP Drw Front % Quality % <85% 99% 14% Travel Ft % Floor Space Sq. Ft %

75 Measure Before After Improve Team Productivity Labor Min/Drw % Lead Time Days % WIP Drw Front % Quality % <85% 99% 14% Travel Ft % Floor Space Sq. Ft % Energy kwhr/drw

76 Standardizing Success!

77 It s About Team Building Front Row Viral Shah Sarah Moore Dee Dee Mullins Dennis Armstrong Back Row Leon Powers Facilitator Greg Akers Earl Kline Dave Prater - Team Leader

78 To Solve Problems State clear goal Develop and maintain an organized, safe, clean, high performance work environment that instills order and standardization into the RCM value stream. Quantify Objectives Implement a minimum of 3 safety improvements. Implement a 5-S improvement. Revise Standard Work Create flow Improving throughput by 50% Improve worker productivity by 50%

79 Lean is not Mean

80 Changing the culture...