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Line balancing and its formulation

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Line balancing and how the productivity can be optimized through the help of formula and by working of 4Ms

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Line balancing and its formulation

  1. 1. Line Balance of a manufacturing plant (Assembly)
  2. 2. By Avijit Biswas Course agendaCourse agenda • Introduction : What is line balancing? • Where do we use line balancing? • Example • Line Balance – A simple example • Pre-requisites for line balancing… • The benefits of the pre-requisites • Method • Visual management • Summary - flowchart
  3. 3. By Avijit Biswas Introduction : What is line balancing? Everyone is doing the same amount of work Doing the same amount of work to customer requirement No one overburdened No one waiting Everyone working together in a BALANCED fashion Variation is ‘smoothed’ What is Line Balancing
  4. 4. By Avijit Biswas Introduction : What is line balancing?
  5. 5. By Avijit Biswas Introduction : What is line balancing? Single Piece Flow
  6. 6. By Avijit Biswas Example :Example : Line Balance ChartLine Balance Chart This is a VISUAL production tool that enables the planning and organisation of individual, TIMED items of work to create the foundation for a balanced production line. It is used as a tool to continuously drive out waste from operations and processes and it is also a valuable tool in implementing changes in customer demand,
  7. 7. By Avijit Biswas Line Balance : Simple Example 1 2 3 4 25 mins5 mins 15 mins 10 mins Constraint Overburden This operator must WAIT for operator 2 Overproduction which causes the other 6 wastes Waiting Over-processing Inventory Rework Transportation Motion This operator must WAIT for operator 3 5 10 15 20 25 1 2 3 4 mins
  8. 8. By Avijit Biswas Line Balance : Simple Example 5 10 15 20 25 Redistribute the work 1 2 3 4 15 mins15 mins 15 mins 10 mins Promotes one- piece FLOW Avoids overburden Minimises the 7 wastes Reduces Variation
  9. 9. By Avijit Biswas Pre-requisites to line balancing… StandardiseStandardise Calculate TaktCalculate Takt Achieve CONSISTENCY in operations Enabling us to achieve our customers requirements by ‘managing our production effectively’ Variation in our operations demands more human intervention which, increases the risk of HUMAN ERROR Understand the ‘drumbeat’ of the CUSTOMER
  10. 10. By Avijit Biswas Takt Time Takt is a German word It is the principal that all activity within a business is synchronised by a pulse, set by the customer demand It describes the metronome Takt = total time available* total customer demand
  11. 11. By Avijit Biswas Customer demand = 10 units / month Total time available = 20 days Drumbeat = 1 part every 2 days Each process needs to complete one unit every 2 days Process 1 Process 2 Process 3 Customer Every 2 days Process 4 Process 5 Takt time Takt = total time available total customer demand Every 2 days Every 2 days Every 2 days Every 2 days
  12. 12. By Avijit Biswas Standardise Highlight key information Operation sequence From: To: Cell/ Area Description: Part No. Quality check Safety precaution Std in process stock Qty of SIPS Takt Time Cycle time Standard work layout Name / position Date Name / position Date Name / position Date Scale: stores Work station 1 Work station 2 Tool cabinet PPE MUST BE WORN AT ALL TIMES 6 Work station 3 Capture the layout Indicate how the work flows
  13. 13. By Avijit Biswas Standardise NO REVISION DATE LOCATION: SHEET……..OF……… DEPT: DATE: PREPARED BY: AUTHORISATION: WORK INSTRUCTION SHEET OPERATION NO. OPERATION DESCRIPTION NO MAIN STEPS Q S E KEY POINTS EXPLANATION/ EXAMPLES/ DIAGRAMS P.P.E. JIGS/ TOOLS REQUIRED CHECKS TRAINING COMMENTS TIME MEPUM WP HRS PEGS REF: TL TL TL PUM ME OPERATING DESCRIPTIONNO As per PEGS requirement
  14. 14. By Avijit Biswas The benefits of the pre-requisites Takt time Standard Operations What do you think are the benefits?
  15. 15. By Avijit Biswas Takt time maximises the productivity due to: • Easily managed processes • Output of each process matches customer demand Standard Operations provide: • Capable and repeatable processes • Process control at source • Improves accuracy of planning • Better adherence to plans • A platform from which continuous improvement can be made • Reduced costs • Improved quality • Basis for training The benefits of the pre-requisites
  16. 16. By Avijit Biswas Method - capture current state Customer demand = 19 units a month Time available = 20 days a month TAKT = Available time Customer demand TAKT = 25 hrs TAKT = 20 days 19 units ( x 24 hrs in a day) TAKT Total work content Line Balance Ratio Line Balance Efficiency 25hrs Current State Ops 3 Calculate TAKT
  17. 17. By Avijit Biswas Method - capture current state Why video? - Used to visually record activity - Accurate method of recording - Irrefutable and unambiguous - Modern approach to establishing method 4. Identify which of the elements are Value-added and which are non-value added 1. Capture a representative sample of the process 2. Review the video with the operators present 3. Break down the ‘elements’ of work and record a time for each one Calculate TAKT Time the process
  18. 18. By Avijit Biswas Method – capture current state Calculate Takt time Time the process Break down the work elements g The operators cycle is broken down into elements These elements are put into three main categories, these being : 1. Working (man or machine) 2. Walking 3. Waiting COMPANY DATE ORIGINATOR CHECKED PART NAME SECTION PART NUMBER VOLUME PROCESS TAKT TIME SEC WORKING SEQUENCE MANUAL AUTO WAIT WALK KEY: Manual Walk ISSUER¨ COORDINATOR¨ MGR¨ ISSUER Auto Waiting TIME OPERATION TIMEOPERATION NAME STANDARDISED WORK COMBINATION TABLE TOTAL 10 3 4 1 10 4 2 15 2 0 0 0 1 Fit bracket A Walk to bench Inspect 1 Machine 2 10 5 TAKT 18 of 43
  19. 19. By Avijit Biswas Method - capture current state Calculate total work content (stacked time) : 15 + 30 + 17 = 62 hrs Takt Line Balance Ratio Line Balance Efficiency 25 hrs 62 hrs Current State Ops 3 Total work content Constraint – customer demand not being met 30 25 20 15 10 1 2 3 5 Takt (25 hrs) 15 30 17 Draw current state Line Balance Calculate Takt time Time the process Break down the work elements
  20. 20. By Avijit Biswas Method - capture current state Or alternatively ….. 1. Identify the business area to be balanced Machining Treatments Assembly 4. Agree estimated time for each job and number of operators involved i. Estimate a time for each sub element ii. Add up all the elements iii. Write on the main ‘post it’ the total time and total operators Is it 1, 5 or 10 hours (use a rough guide) Total estimated time Number of operators 1 5 hrs 2 2 5hrs 1 3 1 5 hrs 2 2 5hrs 1 1 5 hrs 2 2 10hrs 1 1 5 hrs 2 2 1hr 1 3. Break down each process by task i. Use ‘post it’ notes ii. Write on the process name iii. Place on a board in sequence Op1 Op 2 Sub elements of work Main process steps 2. Form small group with team leaders/ operators
  21. 21. By Avijit Biswas Method - capture current state 1 5 hrs 2 2 5hrs 1 3 1 5 hrs 2 2 5hrs 1 1 5 hrs 2 2 10hrs 1 1 5 hrs 2 2 1hr 1 • Lay all the ‘post its’ out in sequence so that all of the processes are visible • Draw on the TAKT line (or use string) TAKT Calculate TAKT Time the process Draw current state Line Balance Break down the work elements 2 5hrs 1
  22. 22. By Avijit Biswas Method - capture current state Target Manpower = Total Work Content Takt time = 2.48 = 3 operators Takt time = 25 hrs Total work content = 62 hrs 30 25 20 15 10 1 2 3 5 Takt (25 hrs) 15 30 17 Calculate Takt time Time the process Draw current state Line Balance Calculate target manpower Break down the work elements Takt Line Balance Ratio Line Balance Efficiency 25 hrs 62 hrs Current State Ops 3 Total work content
  23. 23. By Avijit Biswas Method – capture current stateLine balance ratio = Total work content No. of stations x longest operation Line balance Efficiency = Total work content Target manpower x Takt Line Balance Ratio = 62 hrs (3 x 30) X 100 = 69% Line Balance Efficiency = 62 hrs (3 x 25) X 100 = 83% Takt Stacked time Line Balance Ratio Line Balance Efficiency 25 hrs 62 hrs Current State Target manpower 3 69% 83% What could be achieved without reducing waste and still meeting TAKT – simply REBALANCING!! 30 25 20 15 10 1 2 3 5 Takt (25 hrs) 15 30 17 Calculate Takt time Time the process Draw current state Line Balance Calculate Line Balance Ratio & Efficiency Calculate target manpower Break down the work elements
  24. 24. By Avijit Biswas Method – balance toTAKT example Target 83% Efficiency 30 25 20 15 10 1 2 3 5 Takt (25 hrs) 15 30 17 1 2 3 25 25 12 Takt (25 hrs)30 25 20 15 10 5
  25. 25. By Avijit Biswas Method – balance to TAKT Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? No Yes Complete work instruction (standardise) & implement No 30 25 20 15 10 1 2 3 5 Takt (25 hrs) 15 30 17 1. Identify the elements of work that exceed TAKT 2. Refer to Standard Work Combination table 3. Identify where work can be re-allocated COMPANY DATE ORIGINATORCHECKED PART NAME SECTION PART NUMBER VOLUME PROCESS TAKT TIMESEC WORKING SEQUENCE MANUALAUTOWAITWALK KEY:Manual WalkISSUER¨ COORDINATOR¨ MGR¨ ISSUER Auto Waiting TIME OPERATION TIMEOPERATION NAME STANDARDISED WORK COMBINATION TABLE TOTAL 10 3 4 1 10 4 2 15 2 0 0 01 Fit bracket A Walk to bench Inspect 1Machine 2 10 5 TAKT
  26. 26. By Avijit Biswas Method – balance toTAKT Or alternatively…… 1. Refer to the ‘post it’ notes on the wall 3. Using the experience of the team leaders/ operators, invite them to rebalance the work to below TAKT 2. Use magnetic strips to signify the ‘post it’ notes (elements of time) 1 5 hrs 2 2 5hrs 1 3 1 5 hrs 2 2 5hrs 1 1 5 hrs 2 2 10hrs 1 1 5 hrs 2 2 1hr 1 Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? No Yes Complete work instruction (standardise) & implement No
  27. 27. By Avijit Biswas Method – Identify value added and non-value added time What is Value added and non-value added time? Value Adding: Any process that changes the nature, shape or characteristics of the product, in line with customer requirements e.g machining, assembly Non-Value Adding,but unavoidable with current technology or methods. Any work carried out that does not increase product value e.g inspection, part movement, tool changing, maintenance Waste All other meaningless, non-essential activities that do not add value to the product you can eliminate immediately e.g. looking for tools, waiting time And don’t forget !!
  28. 28. By Avijit Biswas Method – Identify value added and non-value added time Value Added Waste Traditional Focus • Work Longer-Harder-Faster • Add People or Equipment Lean Manufacturing • Improve the Value Stream to Eliminate Waste LEAD TIME
  29. 29. By Avijit Biswas Method – reduce non-value added time and eliminate waste Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? No Yes Complete work instruction (standardise) & implement No COMPANY DATE ORIGINATOR CHECKED PART NAME SECTION PART NUMBER VOLUME PROCESS TAKT TIME SEC WORKING SEQUENCE MANUAL AUTO WAIT WALK KEY: Manual Walk ISSUER¨ COORDINATOR¨ MGR¨ ISSUER Auto Waiting TIME OPERATION TIMEOPERATION NAME STANDARDISED WORK COMBINATION TABLE TOTAL 10 3 4 1 10 4 2 15 2 0 0 0 1 Fit bracket A Walk to bench Inspect 1 Machine 2 10 5 TAKT So, identify the category of work on the standard work combination table 29 of 43
  30. 30. By Avijit Biswas Method – balance to TAKT Detail each process step (on format above) Indicate whether the work is : • Wait • Walk • Work Now you can split the operations on the board into elements of Value added and non value added work Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? No Yes Complete work instruction (standardise) & implement No Or alternatively…
  31. 31. By Avijit Biswas Method – reduce non-value added time and eliminate waste Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? No Yes Complete work instruction (standardise) & implement No Highlight the Value added and the non-value added work elements on the line balance board Non value added activity Value added activity Takt (25 hrs) 1 2 3 5 30 25 20 15 10 Use red strips to signify non-value added work
  32. 32. By Avijit Biswas Method - reduce non-value added time and eliminate waste Takt Stacked time Line Balance Ratio Line Balance Efficiency 27 hrs 57 hrs Future State Ops 2 Non value added activity Value added activity •Reduce the NVA activity by applying waste removal tools (changeover reduction, 5C, process mapping etc) Attack the red, redistribute the green !! 1 2 3 5 30 25 20 15 10 Takt (25 hrs) Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? No Yes Complete work instruction (standardise) & implement No
  33. 33. By Avijit Biswas Method – re-allocate & re-balance 1 2 3 5 30 25 20 15 10 Takt (25 hrs) 1 2 3 5 30 25 20 15 10 Takt (25 hrs) Operator freed up for other process or improvement team Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? No Yes Complete work instruction (standardise) & implement No
  34. 34. By Avijit Biswas Method - update the calculations Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? No Yes Complete work instruction (standardise) & implement No Line balance ratio = Total work content No. of stations x longest operation Line balance Efficiency = Total work content Target manpower x Takt Line Balance Ratio = 44 hrs (2 x 24) X 100 = 92% 1 2 5 30 25 20 15 10 Takt (25 hrs) Line Balance Efficiency = 44 hrs (2 x 25) X 100 = 88% Previous balance ratio = 69% Improvement of 23% Takt Total work content Line Balance Ratio Line Balance Efficiency 25 hrs 44 hrs Future State Ops 2 92% 88%
  35. 35. By Avijit Biswas Method - Continuous Improvement Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? Yes Complete work instruction (standardise) & implement No Value Added Waste LEAD TIME Continuously use waste elimination tools P DC A Plan DoCheck Act
  36. 36. By Avijit Biswas Method - standardise Highlight key information Operation sequence From: To: Cell/ Area Description: Part No. Quality check Safety precaution Std in process stock Qty of SIPS Takt Time Cycle time Standard work layout Name / position Date Name / position Date Name / position Date Scale: stores Work station 1 Work station 2 Tool cabinet PPE MUST BE WORN AT ALL TIMES 6 Capture the NEW layout Indicate how the work flows Scale: stores Tool cabinet Work station 3
  37. 37. By Avijit Biswas Method - standardise NO REVISION DATE LOCATION: SHEET……..OF……… DEPT: DATE: PREPARED BY: AUTHORISATION: WORK INSTRUCTION SHEET OPERATION NO. OPERATION DESCRIPTION NO MAIN STEPS Q S E KEY POINTS EXPLANATION/ EXAMPLES/ DIAGRAMS P.P.E. JIGS/ TOOLS REQUIRED CHECKS TRAINING COMMENTS TIME MEMgr WP HRS PEGS REF: TL TL TL PUM ME OPERATING DESCRIPTIONNO
  38. 38. By Avijit Biswas Visual Management The new line balance chart should be displayed on the cell The impact of changes in resource or Takt on operator cycle times can be seen instantly Opportunities for Kaizen activities can be easily identified
  39. 39. By Avijit Biswas Summary Capture the current state Balance to TAKT & eliminate waste Update calculations Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Can this be improved? Yes Complete work instruction (standardise) & implement No Balance to TAKT Reduce Non Value Added and eliminate waste Re-allocate work & re-balance Update calculations Can this be improved? Complete work instruction (standardise) & implement Takt Total work content Line Balance Ratio Line Balance Efficiency 25 hrs 44 hrs Ops 2 92% 88% Future State Takt Total work content Line Balance Efficiency Line Balance Ratio 25 hrs 62 hrs Current State Operators 3 69% 83% Calculate Takt time Time the process Draw current state Line Balance Calculate Line Balance Ratio & Efficiency Calculate target manpower Break down the work elements Calculate Takt time Calculate Line Balance Ratio & Efficiency Time the process Break down the work elements Draw current state Line Balance Calculate target manpower 2 5hrs 1
  40. 40. By Avijit Biswas Line Balancing Problem A B C 4.1mins D 1.7mins E 2.7 mins F 3.3 mins G 2.6 mins 2.2 mins 3.4 mins
  41. 41. By Avijit Biswas Questions? • 1. What is the bottleneck? • 2. What is maximum production per hour? 60/4.1=14.63 units • 3. What is efficiency and balance delay? • 4. How to minimize work stations? • 5. How should they be grouped? • 6. New efficiency? 4.1 minutes
  42. 42. By Avijit Biswas Calculate efficiency • A. 73.2% • B. 56.7% • C. 69.7% • D. 79.6% • E. 81.2% A B C 4.1mins D 1.7mins E 2.7 mins F 3.3 mins G 2.6 mins 2.2 mins 3.4 mins
  43. 43. By Avijit Biswas (2.2+3.4+4.1+2.7+1.7+3.3+2.6) 4.1x7 20 28.7 69.7% 1-69.7%=30.3% Balance Delay
  44. 44. By Avijit Biswas Number of Work Stations ( ) timecycle timestask TM ∑= (bottleneck) 20 4.1 = 4.88 work stations
  45. 45. By Avijit Biswas Line Balancing Solution A B C 4.1 D 1.7 E 2.7 F 3.3 G 2.6 Station 1 Station 2 Station 3 Station 4 2.2 3.4 All under 6 minutes? (6.0) (5.6) (5.8) 4 Stations 20/24=83.3% Max prod./hour 60/6 10 units/hour
  46. 46. By Avijit Biswas Line Balancing Problem A B C 4.1mins D 1.7mins E 2.7 mins F 3.3 mins G 2.6 mins 2.2 mins 3.4 mins 5.6 5.0 20/5.6x5 = 20/28 = 71.4% 5 Stations Max Prod./hour 60/5.6 10.7 units/hour
  47. 47. By Avijit Biswas 40 secs 59 secs 84 secs 34 secs 56 secs 45 secs What is the minimum # of work stations? Round down. A. 3 B. 2 C. 4 D. 5 E. 6
  48. 48. By Avijit Biswas ( ) timecycle task times∑=TM 40+59+84+56+34+45 = 318 318/84 = 3.78 or 3 work stations What is the efficiency with 6 operators? ( ) ( ) ( )( ) ( )100 timecyclestationsofnumber task times %Efficency ∑= 318/6 x 84= 318/504 = 63%
  49. 49. By Avijit Biswas ( ) ( ) ( )( ) ( )100 timecyclestationsofnumber task times %Efficency ∑= 40 secs 59 secs 84 secs 34 secs 56 secs 45 secs 99 secs 118 secs 3 Stations ? 318/3x118 318/354 = 89.8% 101 secs
  50. 50. By Avijit Biswas 40 secs 59 secs 84 secs 34 secs 56 secs 45 secs 4 Stations?99 secs 84 secs 56 secs 79 secs 318/4 x 99 = 318/396 = 80.3%

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