What can traffic in stockholm teach you about queuing theory - Lean Kanban Central Europe 2011
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The document discusses the principles of queuing theory in the context of traffic management, emphasizing the importance of understanding bottlenecks and their impact on throughput and cycle time. It outlines strategies to exploit, subordinate, and elevate bottlenecks to improve process efficiency while maintaining a balance between demand and flow. The author, Håkan Forss, stresses the need to avoid inertia that may cause system constraints and promote a consistent workflow.
What can traffic in stockholm teach you about queuing theory - Lean Kanban Central Europe 2011
- 1. What can traffic inteach you aboutqueuingtheoryHåkan Forss - [email protected] - @hakanforss
- 2. Håkan Forss Lean/Agile CoachHåkan Forss - [email protected] - @hakanforss
- 8. Little’s Law1212 / min1 min =
- 9. Little’s Law612 / min0,5 min=
- 10. Little’s Law2412 / min2 min =
- 11. 20 sec40 secWith less Work-In-ProcessShorter cycle timeBetter time to marketFaster feedbackMakes problems visible fasterAre we working on the right things
- 15. 5
- 16. Don’t allow inertia to cause a system constraint.
- 19. Capacity = 4Capacity = 6Capacity = 6Throughput = 4You can never go faster than your bottleneckThe capacity at the bottleneck will dictate the capacity of the complete process
- 20. Capacity = 4Capacity >= 4Capacity = 6Throughput = 4You can never go faster than your bottleneckAs long as capacity in front of the bottleneck is equal to or grater than the bottleneck you will go as fast as your bottleneckFull use of a higher capacity in front of the bottleneck will make cycle time go up
- 21. Capacity = 4Capacity = 6Capacity >= 4Throughput = 4You can never go faster than your bottleneckAs long as capacity is equal to or greater after the bottleneck you will go as fast as your bottleneckHigher capacity after the bottleneck than at the bottleneck will not improve throughput over time
- 22. Don’t allow inertia to cause a system constraint.
- 26. Bottleneck at the end of the processWork is backing upSlowing down the processCycle times goes up
- 28. Bottleneck at the beginning/middle of the process Work is drying up at the end of the processmaking workers idle
- 31. ?
- 33. Non-instant availability resourceLooks like a bottleneck
- 34. Non-instant availability resourceA resource that is not available all the timeHas required capacity but is not instantly available
- 37. Don’t allow inertia to cause a system constraint.
- 38. Exploit your bottleneckBottlenecks should only work on bottleneck activitiesDo whatever you can to make your bottleneck 100% utilized Try your hardest to avoid problems at you bottleneck Time lost at the bottleneck is time forever lost for the process
- 39. Don’t allow inertia to cause a system constraint.
- 41. Subordinate to your bottleneckDo what you can to always have work for the bottleneckDo what you can to avoid passing defects on to the bottleneckSub optimal performance for non bottlenecks can be accepted
- 42. Subordinate to your bottleneckTry to use you over capacity to alleviate the bottleneck of non bottleneck workSub optimal performance for non bottlenecks can be accepted
- 43. Don’t allow inertia to cause a system constraint.
- 45. Elevate your bottleneckExpand the capacity at the bottleneckExpensive as it usually will use bottleneck resources
- 46. Don’t allow inertia to cause a system constraint.
- 48. Don’t allow inertia to cause a system constraint.
- 49. Balance demand to flow
- 50. Wishful thinkingCapacity = 4Demand = 6Balance demand to flowCapacity at the bottleneck will dictate the capacity of the processBalance your demand to a continuous flow through the bottleneckHigher demand than capacity will increase cycle time
- 52. Balance demand to flowAn even flow can stabilize the process Low work-in-progressKeeps cycle time down Makes bottlenecks visible faster
- 54. Slow down to go faster Slowing down can stabilize the process flowA stable process can go faster
- 57. Håkan ForssMail: [email protected]: @hakanforssBlog: http://hakanforss.wordpress.com/
- 58. Recommended readingHåkan Forss - [email protected] - @hakanforss
Editor's Notes
- #19: Every process has at least oneOne is always a number oneWhen you break it number two will take it’s place
- #23: Identify the constraint
- #24: Very busy, all the timeWork piles up in front of themPeople downstream idle
- #34: There are two different types of bottlenecks: - Capacity contraint resource - a resource limited by capacity, like a bottle - non instantly available resource - a resource that is not available all the time
- #35: There are two different types of bottlenecks: - Capacity contraint resource - a resource limited by capacity, like a bottle - non instantly available resource - a resource that is not available all the time
- #38: Exploit the constraint
- #39: No task switchingNo idle timeOnly work on highest priority itemsOnly value-adding workNo wasted effortBest working conditions.
- #40: Subordinate to the constraint
- #41: Only high quality inputDon’twastevaluecreated by bottleneckDrum-buffer-ropeSubordinates need slackShare work.
- #46: Training and toolsCoaching and mentoringTeam retrospectivesIndividual improvementWorkspaceimprovementProcess improvementPairingMore resources