Original course by Janet Smart Lectures by Steve Sheard

1. Original course by Janet Smart Lectures by Steve Sheard C13: Modern Manufacturing Systems

2. Course Summary • Section 1 • • Trends shaping Modern Manufacturing • – Historical: Quality revolution • Impact on manufacturing • – Present: JIT and Continuous Improvement, • Mass Customisation • Section 2 • • Layout of Manufacturing Systems • – Design of a system for modern, flexible manufacturing • – Job shops, cells, process layout

3. Course Summary • Section 3 • Dynamics of manufacturing systems • – When products start to move, problems happen • – MUDA and Group Technolgy • – Continuous improvement • Section 4 • • Planning, Scheduling and Control • – The scheduling problem • – Scheduling algorithms and heuristics • – Examples with precedence

4. Section 1: Trends ShapingModern Manufacturing • Trends shaping Modern Manufacturing • – Historical: Quality revolution • Impact on manufacturing • – Present: JIT and Continuous Improvement, • Mass Customisation

5. History: The Bad Old Days See “Modern Times” Charlie Chaplin, 1936 – http://www.youtube.com/watch?v=IjarLbD9r30&feature=related“I’m All Right Jack” Peter Sellers, 1959 • Work Characteristics – Piecework – Stressful working conditions – Boring – Lack of control over one’s own work – Poor conditions due to lack of infrastructure investment • • Factory characteristics • – Low productivity • – Low quality goods • – Lack of innovation • – Poor customer relations • – High levels of waste • – High inventory levels

6. Undesirable consequences • Facilities were run at full capacity, but companies failed to invest in new equipment and product development • Operating costs were reduced by cutting maintenance and exceeding operating capacity • Work in Progress (WIP) spent large amounts of time waiting between process steps • Factories were often at panic levels to fulfil routine orders

7. Motivator for Change • The Japanese manufacturing revolution • Focus on quality and reducing waste • Japanese began offering products of superior quality at lower cost than home manufacturers • Applied scientific, statistical methods to measure and control quality of products

8. What happened? • Stunned the West in 1970s and 1980s • Japanese approach proved difficult to reproduce • Ended or reduced many Western industries– e.g. motorbikes, consumer electronics, automobiles

9. Consequences for UK and Western Manufacturing • Decimation of automotive and motorcycle industries led to the loss of suppliers and supporting industries • Failure to compete was due to poor manufacturing quality, lack of new product innovations and poor reliability of delivery … but how did is happen?

10. Frederick Winslow Taylor(1856 –1915), American mechanical engineer • Taylorism: • See “Principles of Scientific Management” published in 1911. • Taylor applied scientific methods to optimise production efficiency, using illustrative examples in this article.

11. Frederick Winslow Taylor(1856 –1915), American mechanical engineer • Taylorism: • Break manufacturing task into small and simple segments which can be analysed and scheduled. • Now “scientifically” put the right person into the right job - the one they are best suited to do - and to calculate the maximum achievable (and therefore expected) rate of production, incentivised with money.

12. Frederick Winslow Taylor(1856 –1915), American mechanical engineer • Taylorism: • Henry Ford took guidance from Taylor when introducing the moving production line to mass produce the Model T car (see later). • Following Ford, America and Europe interpreted Taylorism with a “stop watch” mentality, that aimed to punish workers for not maintaining targets.

13. Frederick Winslow Taylor (1856 –1915), American mechanical engineer • The Japanese were inspired by Taylor but took their insights in a different direction. • The Japanese chose to improve productivity by engaging with the workforce, rather than measuring and monitoring them. • They adopted a spirit of cooperation rather than intimidation.

14. W. Edwards Deming • Father of “Quality” movement • Statistics professor at New York University in 1940s (originally an electrical engineer) • After World War II, Japanese economy devastated by the war and reparations • Deming helped Japanese companies to improve quality • Not competition but cooperation that matters most

15. W. Edwards Deming • Founder of the continuous improvement model “Plan-Do-Check-Act” – see later • Made a significant contribution to Japan's reputation for high-quality products and consequently its economic power • Challenged traditional views of punishment and reward of workers, used statistical analysis of performance • http://en.wikipedia.org/wiki/W._Edwards_Deming

16. Some of Deming’s 14 points • Commitment of upper management in a company’s quality improvement effort • Cannot blame poor quality on workers • Only 15% of quality problems due to worker error • 85% due to poor processes, management and systems

17. Genichi Taguchi(1924 – 2012), Japanese engineer and statistician • Taguchi is credited for developing methods for enhancing quality and reliability in manufacturing by applying statistics • He rejected the traditional view that products were either pass or fail in terms of acceptable quality

18. Traditional perception of quality Product Quality Below spec. Above spec. Performance LS Target US Quality viewed as step function, i.e. product is uniformly good or bad. (LS = lower specification, US = upper specification).

19. Traditional perception of quality A Product Quality B Performance LS Target US Quality viewed as step function, i.e. product is uniformly good or bad. (LS = lower specification, US = upper specification). In practice we get curves A and B.

20. Traditional perception of quality • But…… • Curves A and B represent the frequencies of performance of two designs during a certain time period. • B has a higher fraction of “bad” performance and therefore is less desirable than A.

21. Taguchi Loss Function Customer displeasure Increasing cost Loss function or customer dissatisfaction $ costs too much Performance LCT Target UCT Taguchi believed that the customer becomes increasingly dissatisfied as performance departs farther away from the target

22. Taguchi Loss Function He suggested a quadratic curve to represent customer's dissatisfaction with product performance. The curve is centred on the target value, which provides the best performance in the eyes of the customer. Identifying the best value is not an easy task. Targets are sometimes the designer's best guess. LCT represents lower consumer tolerance and UCT represents upper consumer tolerance.

23. The Quality revolution

24. Lean manufacturing: The goal? • Drive out waste • Eliminate whatever does not add value • Increase flexibility • Improve efficiency • Identify and eliminate problems JIT is a concept within Lean Manufacturing

25. JIT and Inventory:Traditional v’s JIT approach • Traditional approach encourages large inventory, i.e. a large number of finished goods held in the factory as a buffer • JIT Approach –Make a small batch of each product every day –Eliminate all sources of waste, i.e. anything that does not add value –Provide the right part, at the right place, at the right time –Utilise the full capabilities of the workers

26. Just in Time: Principles • • Only manufacture what is needed and when it is needed so that there is no excess production • Inventory (i.e. stock in the warehouse) drastically reduced, removing costs associated with holding stock items • Example: BMW Mini factory will only start making a car once an order has been placed (their suppliers also operate a JIT delivery)

27. Just in Time: key steps • Create a Production Schedule, considering all steps in the production process • Level the schedule – roughly the same products in the same sequence each day – fixed for a few months into the future • Implies constant demand on all work centres and suppliers - CONWIP (Constant Work in Progress)

28. Stages of implementing JIT • 1. Obtain management commitment • 2. Involve workforce. Begin training. • 3. Start with final assembly line • Level production to be nearly identical each day • Reduce setup times • Introduce standard containers

29. Stages of implementing JIT II • 4. Work backwards from final assembly • Reduce setup times • Move inventory from stores to shop floor • Match lot sizes to those in final assembly 5. Balance production rates for each work centre, adding capacity where necessary 6. Extend JIT to suppliers

30. JIT: Relationship with suppliers • Suppliers must supply frequently (up to four times per day) • Usually located close by, on same site, or in same building • Must deliver perfect quality • Business partners, not adversaries

31. Just in Time: KANBAN • Kanban approximately means “visible card or sign” • Simple but effective idea introduced by Toyota car company in 1950’s to improve JIT process • Products manufactured in the factory are pulled through the process using kanbans (containers) • Visual method for tracking Work-in-Progress (WIP) throughout the factory, can be a physical container but also a simple sign or marker

32. Very simple concept of kanban

33. JIT: Role of the Kanban • System for pulling parts from one work centre to the next • Parts are kept in a fixed number of small containers • When all containers are filled, production is shut off, until an empty container is returned • If one process stops because of quality problems, all preceding processes must stop too

34. Kanban in motion Output area Input area Input area Output Production kanban Work Area B Work Area A Withdrawal kanban – post production

35. Push or Pull: Process based layouts

36. How many containers? where n = total number of containers D = demand rate of using work centre C = container size, number of parts T = time for container to complete whole circuit

37. Inventory controlled by Kanban • Maximum stock that may be held = nC = DT • To reduce maximum inventory, reduce n or C • Remember D is fixed, so must reduce T, the time the container takes to complete the circuit • T includes machine setup time, run time, wait times, time in transit

38. Kanban example • Question: • A company implements JIT manufacturing in a factory arranged into a sequence of 6 assembly workstations operating for 8 hours per day. • Work-In-Progress (WIP) is moved to each workstation in turn until completed. • Assuming WIP is carried between workstations in kanbans and each workstation takes 20 minutes to complete its process determine the total WIP in the factory if the demand is 216 products per day.

39. 1 2 3 4 5 6 Kanban example • Answer: (using WIP = nC = DT) • The demand per hour is 216/8, i.e. D = 27 products/hr. • A single kanban takes 20 minutes × 6 to move completely through the assembly process, so T = 2 hours. • Assuming the process is meeting demand, then WIP = 2 × 27 = 54 partly assembled products (i.e. each kanban holds 9 items of WIP).

40. JIT and workforce • Workers must be multi-skilled, able to • run machines • do setups • perform routine maintenance • Workers given responsibility for detecting defects and shutting down production (i.e. stop production of defective products) • Everyone must be engaged in constant improvement of production processes • Everyone must be convinced of benefits of JIT

41. Continuous Improvement • The market and environment are constantly changing, so must constantly adapt • Plan Do Check Act – the problem solving cycle

42. Check – Gather and analyse data – Achieved desired goal? Act – Identify training and system changes to establish new practice – Continue to monitor and look for further improvements Plan Do Check Act cycle • Plan • – Identify the problem • – Establish a goal • – Map the process • – Identify possible causes • Do • – Generate possible solutions • – Select one and implement it

43. ANDON System • Manufacturing term referring to a system to notify management, maintenance, and other workers of a quality or process problem. • Another Japanese word, meaning a traditional paper-lantern. • In a factory it will be a signboard incorporating lights to indicate which workstation has the problem. • The alert is activated manually by a worker using a pull-cord or button, or may be activated automatically by the production equipment itself.

44. Distinctive features of new manufacturing • Substantial investment in new, highly automated equipment, over £100M • Policy of Continuous Improvement • Just in time production and deliveries • Supply network is trans-European • Products made to order • Customised manufacture

45. Mass Customisation • Delivering the customer’s desired option to a price and lead time comparable with mass production • Customer may design their own product from a wide range of options, • Or participate in the design and fabrication of the whole product

46. Structure of an MC system Manufacturing in batches of 1 in response to pull from customer Scheduled according to traditional mass production methods in lots Semi-finished goods Push-pull interface

47. Mass Customisation Strategies • Location of the push-pull interface, defined according to customer involvement point • Post Delivery • Distribute to Order • Assemble to Order • Fabricate to Order • Engineer to Order

48. MC 1 – Post Delivery (PD) • Customer involvement is after delivery • Products are made to stock • Mass Production

49. MC 2 – Distribute-to-Order (D2O) • Customer gets involved prior to the delivery point • Products will be distributed on order

50. MC 3: Assemble-to-Order (A20)