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. Line Balance of a manufacturing plant (Assembly)
- 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. 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. By Avijit Biswas Introduction : What is line balancing?
- 5. By Avijit Biswas Introduction : What is line balancing? Single Piece Flow
- 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. 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. 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. 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. 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. 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. 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. 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. By Avijit Biswas The benefits of the pre-requisites Takt time Standard Operations What do you think are the benefits?
- 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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
- 44. By Avijit Biswas Number of Work Stations ( ) timecycle timestask TM ∑= (bottleneck) 20 4.1 = 4.88 work stations
- 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. 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. 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. 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. 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. 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%
Notes de l'éditeur
- Read through the agenda line by line
- Ask the audience what they know about line balancing Jot down their answers on a flip chart When you have exhausted the responses go through this slide (the points will appear one at a time)
- This slide is meant to be a bit of fun! It simply shows a couple of examples of when a line is NOT balanced – highlighting the OVERBURDEN by some operators and the WAITING of others You can also point out how INVENTORY is being built up. The top drawing shows how LARGE BATCH QUANTITIES create INVENTORY and WAITING The bottom drawing demonstrates how the guy in the middle has obviously got a longer process than the other two therefore creating an IMBALANCE which then creates WAITING and INVENTORY. The chap in front of him is also OVERPRODUCING.
- Here the example shows what a line should look like when it is balanced. This means that all of the operations take near enough the same amount of time. The product can then flow through the line ‘one-piece-at-time’ so that each process receives a consistent supply of product right through to the final customer Here, if quality issues are found then the line has to stop and DEAL WITH THEM! – In the previous example quality issues can be hidden due to the INVENTORY in the system. To avoid affecting the customer with a line stop a ‘standard-in-process-stock’ can be kept between the last operation and the customer. This is a controlled level of stock that compensates for variations in demand / production. At the end of the day, the production needs to be as stable and consistent as possible – like a drum beat!
- This is an example of a line balance chart The Line balancing board is a management tool that visually represents the elements of standardised work in a clear and easy to understand way. The line balance chart serves many purposes ranging from being a very simple “snapshot\layout” of a process to a much more detailed planning and organisation tool . However all it’s functions are used in conjunction with setting up and maintaining manufacturing processes
- This is a simple example. Here we have four processes, each with different process times (depicted below in graph form). As you can see, operation 1 has the shortest time and operator 2 has the longest. Therefore, operator 2 is the CONSTRAINT. This means that operator 2 will have to do more work than the others meaning that he is OVERBURDENED. Since operator 1 has the shortest time it means that either he sits and WAITS for operator 2 or he OVERPRODUCES to fill his time. This creates the INVENTORY that you can see. The other following operations tend to WAIT for Operator 2 also. If Operator 1 does OVERPRODUCE, then this tends to create the other WASTES in the system. The wastes can be identified into 7 categories…..
- If we were to re-allocate some of the work from operator 2 onto lets say operator 2 then we can see how this can make the line more BALANCED. This reduces VARIATION in the process, Minimises the 7 wastes Avoids overburden And promotes one-piece-flow. Once again , all of these attributes help achieve a stable work environment in which variations can be detected quickly and dealt with. The customer or final in-process-stock also receives a consistent supply of product. Due to the low level of inventory in the system, if the customer changes his order drastically the system allows you to be flexible as you do not have to scrap large amounts of stock. Rather than working in batches, this system also encourages you to change over more frequently. At first this may be an issue as the process may not be set up for this. However, this is where change over reduction activities can be used
- These are the two pre-requisites to line balancing. Takt time is simply the ‘time available to produce components in a year’ divided by the ‘customer demand’ giving you a drum beat of customer demand. I f we know how many products we need to produce at regular intervals then we can balance production to meet this. Ensuring that we always meet our customer requirements. It also enables us to calculate the required level of manning for production also. STANDARDISE – what we mean by this is STANDARDISING the operations so that we have a base line on how the job should be completed. This enables better management of the process and problems or variation from the process can be determined more effectively. This is vitally important as one-piece-flow demands that you are able to resolve issues quickly. Otherwise you will stop the customer ultimately!!
- (READ SLIDE)
- If you were required to produce 10 units a month, then a in a 20 day month you would simply need to produce 1 unit every 2 days. This also enables you to visually manage your production more effectively. If you know that you are to produce a component every two days then you know that after 1 day you should have completed 50% of that component, and at lunch time you should be 25% of the way into completing the first part. If for any reason this is not the case then production management need to understand why that is the case and react accordingly (using problem solving techniques and escalating the issue if necessary). Visibly displaying this situation enables management to closely manage production more effectively. This enables adherence to TAKT (customer requirement) and makes sure that issues are resolved as they occur. In this way the issues that occurred frequently in the past will gradually decline in there occurence creating a more stable environment. In this stable environment people can spend more time focusing on continuous improvement of the process and resource can be freed up for other activities.
- Standard formats are popular tools for detailing the way that process should be run or managed. Here is an example of a ‘Standard work layout’ document which would be used to detail: How the cell should be layed out (position of machines/ people / Stock locations How the material should flow through the area. Highlighting Health and safety information. This document should be signed off by the team leaders of the area and the local area manager. It should be visibly displayed in the area for all to see (along with other standard documents or on a visual management board.
- This standard is really the ‘manufacturing way’ If the process is detailed in this way and worked to then the process becomes more manageable and is a ‘stake in the ground’ for improvements to made
- Ask the audience why THEY think TAKT and STANDARD OPERATIONS are important pre-requisites. Jot their answers on a flip chart Discuss their responses (10 minutes)
- If the audience has not been able to come up with all of the answers then read through this slide as a back up.
- So now we are moving into the actual method of line balancing. The next few slides detail an example which we are going to work through. The first thing to do do is to calculate TAKT. Read through slide You will notice at the bottom right of the page that we are going to keep a record of some of the key information from each slides.
- This is the best way for capturing the data Waste and NVA can be identified more easily and can allow the team to spot things that they previously didn’t realise occurred. Videoing a process is more difficult than you think. You must concentrate on capturing the process (not the man). Sometimes the operator may be unavoidable, in these cases it may be prudent not to capture his mugshot!!
- After videoing the process the video must be reviewed WITH THE TEAM. Another standard document that should be used at this stage is called a ‘STANDARD WORK COMBINATION TABLE (SWCT). This document is used for detailing each of the process elements that can be seen from the video. It is then used to highlight VA / NVA and waste and detail the time. The TAKT can then be seen clearly and the operations can be sketched out along the time frame. This document is the record of how the job is actually carried out and can be used at a later stage for balancing the work out between operators.
- Use some red and green lego to demonstrate this It may be a good idea to use a hard copy of the table so that the attendees can fill it out as you go
- VSM can be used to identify the area to be studied A cross functional group with varying levels of experience is preferred Write on post-it notes the process name and the estimated time. Try to gain as accurate a picture as possible
- The post its can be stuck onto the brown paper to create ‘little towers’ of process times. The TAKT line is also drawn on at this stage
- The target manpower is calculated by adding up the total work content of the job and dividing it by the TAKT. This will give you something to aim for as it will tell you how the process could (in terms of the manpower required) run without any efficiency losses in a perfectly balanced state. If the figure comes out as 2.48 (as in the example) then you will have to round the figure up to 3 and except that there will be some spare capacity in the cell. If however, the it comes out as 2.02 or 2.1 then you can justify only using 2 on the basis that the 0.1 could be reduced through continuous improvement.
- This tells you that without making any improvements in the process, the customer demand can be met and a efficiency of 83% can be achieved
- The objective now is to balance all of the timed elements of work to TAKT.
- At this point give out the SWCT hand out
- This is the method that can be used without video equipment. It is based on estimates but is very visual and imbalances can be noticed very easily.
- As the video is being reviewed it is important to get the operators to identify what elements of work are Value added, Non-value added, and Waste. Read through the descriptions of each on the slide. Value added – example – when a drill is actually cutting metal (not moving into the work piece) Non-value added – example – inspection, putting a part in a jig, Waste – T.I.M.W.O.O.D - The 7 wastes are : Transportation, Inventory, Motion, Waiting, Overproduction, Over-processing, defects
- Read the slide Line balancing is about identifying and eliminating waste from the process and balancing out the remaining work in the most efficient way. Big improvements can be made without even looking at the cycle time of the machine or process. Once the wastes in the system have been minimised then more benefit will be yielded from attacking the VA work. If this doesn’t happen the effects will be hidden, lost or have minimal effect.
- Highlight each of the eliminate in either green or red to indicate whether the work is VA or NVA or WASTE (some formats have columns for VA,NVA,WASTE)
- Read the slide
- This standard is really the ‘manufacturing way’ If the process is detailed in this way and worked to then the process becomes more manageable and is a ‘stake in the ground’ for improvements to made
- Constructing a line balance chart on a white board is the best way for making it visible. Magnetic strips can be cut to represent the NVA and the VA elements. The strips can then be redistributed - simulating the possible effect of a change in resource or Takt time.