DM202 Sem2 Wk3 Design layouts (2).pptx

Manufacturing Management DM202 Semester 2 – Facility Design Colin Andrews: [email protected] Sign in Student password r7tb5n Facilities Design  Aim   Reading  Reid & Sanders Chapter 10 or any other Operations Management book Muther “Practical Plant Layout” Example: https://yo...

Manufacturing Management DM202 Semester 2 – Facility Design Colin Andrews: [email protected] Sign in Student password r7tb5n Facilities Design  Aim   Reading  Reid & Sanders Chapter 10 or any other Operations Management book Muther “Practical Plant Layout” Example: https://youtu.be/NTb3SNtwTjg   To illustrate a number of the practicalities of arranging machines and other equipment Facilities Design  Defining the physical arrangement of the equipment on the shop floor  Assumes:   Location is already known  Products and processes have been identified  Capacities have been calculated  Equipment has been selected Most of following relates to batch manufacture  must always relate to type of product, demand and process Design categories  Facilities Design  where  also  accessories: tooling cabinets, lockers, etc. Materials Handling System Design  how  the equipment is to be located will the material be transferred from one operation to another Production System Design  defining management, organisation and systems (e.g. cells) New factory layout ??? * use templates to position? scale models? computer software? Cost of poor facilities design  Poor layouts incur unnecessary materials handling costs  Material handling does NOT add value  up to 12% of factory costs are caused by materials handling  up to 30% of factory costs may be caused by non-value adding activities  Note: layout and transport closely related. Problems in older factories  Older factory buildings  Column spacing  Low floor to ceiling height  Low roof or mezzanine floor or material handling  Movement between floors / sites  Access for machine movement  Floor strength, Vibrations  Security, Aesthetics  Older machines  Vibrations  Trenches  If it works, don’t touch it!  Transfer lines  Hydraulics - temperature Factory Space includes...  Aisle design  Can  take up to 20% of space  Passing of trucks  Escape holes for staff? Dead zones  Poor  What  layout? can be done with them? Required for machine maintenance? Non-value adding activities • Inspection areas • material handling equipment • raw material storage area • WIP areas • finished goods storage area • tool and fixture storage area • passageways • dead zones Machines need Services  Power  Gas, electricity  Movement of supplies  Computer links  Data collection, e.g. SCADA systems  Machine monitoring and control  Wireless links on the increase  Other  Waste  Compressed  Lighting air Operators need Health & Safety ...       Escape routes Fume extraction - e.g. plating Trapping - e.g. lathes Noise - e.g. presses Height of machine operation Out of reach of hazards  S ’ T I e.g. working with back to aisle  e.g.   E H T W A L underneath crane First aid, fire extinguishers Standards - e.g. minimum working space ! Design Objectives  Objectives  Possible procedure Clear boundaries of areas - ownership. Self contained?  Determine boundaries and equipment availability  Develop machine and other resource databases  Visibility of processes. Good flow   “Compatible processes” adjacent Identify potential problems - can they be overcome?  Housekeeping  Obtain outputs from flow analysis  Acceptance by shop floor (use their input)  Use templates on scale drawing  Invite criticism - especially from shop-floor. Get approval  Develop implementation plan  Re-Cap  Manufacturing Layouts  Functional  Flow Focus for today  Cellular  Project  Process Design for specific use Design of functional systems  Aim  To illustrate a range of techniques for facility design    ‘P/Q’ Product Quantity Analysis Systematic Layout Planning Reading   Operations Management text books, especially by Muther Reid & Sanders Chapter 10, pp.343-359 Some key terms   Bill Of Material (BoM)  Introduced last week  Structured description of all the parts in a product Route Card / Routes / Routing  All the operations required to complete a part  May be a single (assembly) operation on a number of parts  May be a series of (machining) operations on a single blank  Typically card the move between stages of a BoM has a route Route card for this step P-Q Analysis    Product-Quantity analysis developed by Muther Arrange products on chart in order of quantity Can be used for identifying type of layout Quantity of each product  High vol - flow line Medium vol - Lines / cells Low vol - job shop / functional Products (in descending order of quantity) Systematic Layout Planning (SLP)  From 1960’s but …  Work still relevant (See paper on myPlace)  Software packages available to support (e.g. FactoryFlow)  SLP technique developed by Muther  Developed  as methodology (i.e. a pattern to follow) Four phases:  Location  General overall layout  Detailed layout  Installation (Functional) Layout planning  Material based relationships:  the flow of material through the manufacturing processes, as defined by the route cards  Service based relationships:  all the supporting activities involved in the manufacturing process, e.g. stores, tool rooms, maintenance, etc.  Relationships can then be ranked Muther’s Ranking of Relationships  Routes can be ranked Stage 1 Stage 2 Label Comment % routes % intensity of flow A Absolutely necessary 10 40 E Especially important 20 30 I Important 30 20 O Ordinary closeness 40 10 U Unimportant ~ ~ X Undesirable ~ ~ Perform a To / From analysis of operations from the available Route Cards e.g. identifies the following routes: A-B, B-C, B-E, C-D, C-E, C-F, D-E, E-F Take to/from data and the ranking table above and order list of movement relationships can be created Flow between pair of machines Quantity flowing Percentage flowing Intensity rating B-C 6800 27.4 A A-B 4400 17.7 E B-E 3600 14.5 I C-F 3000 12.1 I C-E 2000 8.1 O C-D 1800 7.3 O D-E 1800 7.3 O E-F 1400 5.6 O Totals 24800 100 - Example Activity Relationship Chart (… how to set out the To / From data) Label Comment % routes % intensity of flow A Absolutely necessary 10 40 E Especially important 20 30 I Important 30 20 O Ordinary closeness 40 10 U Unimportant ~ ~ X Undesirable ~ ~ (You must apply judgement here) Activity and space relationship diagrams  … can develop this information diagrammatically Stage 3 Stage 4 A Display important relationships first, then add others B C B C F E Stage 5 Activity/Machine Area required A A 4 B D B 2 C 1 D 1 E 1 C D F 1 Use area data to create space relationship diagram F E Use relationship data to create activity relationship diagram NB Different operations (departments) require different areas to operate Layout plan  The space relationship diagram can be converted into a layout plan  The layout plan will have an “efficiency”  Can calculate the number of adjacent and non-adjacent flows  From this calculate a percentage Stage 6 A C F E D B Summary of SLP RAW DATA TO / FROM CHART TO All values in top right corner to give intensity FROM No. 1 2 3 etc. Move 1 - 8 5 - 7 4 - 5 Qnty 16 15 13 List the movements in order. Calculate % of whole. Use technique to classify into ‘A’, ‘E’, ‘I’, ‘O’, ‘U’ Draw schematic Note: this is only part of Muther’s approach - other parts such as what to do with the arrangement of machines within the departments has not been covered Show space reqts Fit to factory Summary of Functional Layout 1. 2. 3. 4. 5. 6. Numerous tools and techniques available Only a few covered here Tools vary in ease of use and understanding Many are laborious if not embedded in software Each has strengths and weaknesses Important to decide which tools to use when (if at all!) Design of Cellular Layouts  Aim  To illustrate the mechanisms of forming cells.  To show the ROC mechanism  Reading  Burbidge - Production Flow Analysis  Reid & Sanders Chapter 10, pp.367-369  Topics  Need to identify cells  Coding and classification  Production Flow Analysis  Rank Order Clustering (ROC)  Practical issues Forming Families of Products / Parts  Objectives  simple material flow system  each part processed in one group  acceptable workloads on machines in group  easily managed by one person  avoid unnecessary duplication of equipment  Design families  where parts are grouped by design features and should have similar processing requirements  Production families  where parts are grouped by processing requirements, regardless of design General procedure for group formation Procedure  collect data (samples, drawings, routings, etc.)  identify characteristics  classify characteristics  group parts with similar characteristics  by eye - largely subjective  by rule of thumb - rotational parts up to 50mm  by classification and coding  by operations sequence analysis General procedure for group formation Manual exercise - Identify cells in the routing data:  Example shows Part 1 goes to m/c’s 2,3 & 5 Suggest:  Sketch  Draw out machines on paper lines between for flow  Identify Machines 1 any patterns by eye Parts  1 2 3 4 5 6 7 2 x 3 x x 4 5 x x x x x x x x x x x Classification and coding Classification • is the arrangement of items into classes on the basis of their characteristics Shaded squares indicate component code matrix Coding • is assigning a numerical or alphabetic value to the characteristics in order to facilitate classification Example • Aston University “CAMAC” • Diagram: search for cell to use for part • Can reverse process and use iteratively for creation of cells X X X X X X X X X X X X X X X X X X X X X X X Machine cell compound matrix X Component manufactured on these machines CNC Lathe Horizontal mill Cylindrical grinder Hone Production Flow Analysis (PFA) Three stage technique proposed & developed by Burbidge: • Factory flow analysis - broad sub-division of plant into departments – Only really necessary for large systems • Group flow analysis – Machine families on routing regardless of sequence – Can use Rank Order Clustering • Line analysis – Flow between machines to provide sequence – May be obvious flow, if not ... – Can use To/From analysis Original From A B C D E F G H To A B C 15 D 50 E 30 20 10 15 15 10 F G H 30 20 20 70 35 45 65 20 Mechanisms for PFA PFA (Group stage) results in matrix of routing data Need mechanisms to sort that information Key mechanisms are: • Cluster analysis – Cluster analysis based on idea of calculating similarity index and group accordingly • Rank Order Clustering (ROC) – Easier to understand than cluster analysis – Matrix manipulated directly by interchanging rows or columns – Binary numbers • Code rows and columns into binary numbers • Sort rows/cols in descending order • Repeat until no change – Note: easily computerised: ROC software or spreadsheets. ROC - manual example Machines Parts 1 2 3 4 5 6 7 Machines 1 2 0 1 1 0 0 1 1 0 1 0 1 0 0 0 Parts Take initial matrix and sort Random ... 3 1 0 1 0 0 0 1 4 0 1 0 1 0 1 0 5 1 0 0 0 0 0 1 Rank 5 =1 6 =1 4 =1 7 Rank rows... ... order rows Parts 2 4 6 5 1 3 7 Rank Machines 1 2 1 0 1 0 1 0 1 0 0 1 0 1 0 0 1 4 3 0 0 0 0 1 1 1 3 4 1 1 1 0 0 0 0 2 1 2 3 4 5 6 7 5 0 0 0 0 1 0 1 5 Rank cols... ... order cols 1 2 3 4 5 x x x x x x x x x x x x x x ... cells Parts 2 4 6 5 1 3 7 Machines 1 4 1 1 1 1 1 1 1 0 0 0 0 0 0 0 3 0 0 0 0 1 1 1 2 0 0 0 0 1 1 0 5 0 0 0 0 1 0 1 ROC - practicalities  Ignores loading. Ignores sequence.  Depends on accuracy of routing data.  Backward looking - ignores changes planned.  Exceptions / ‘real world’ prevents perfect matrix  Need to use judgment  To ignore certain operations / machines  To split work centres, therefore machines  To visually force solution Cell Design Summary  There are many ways of forming cells  Production Flow Analysis (PFA) covers a number of them  Rank Order Clustering (ROC) is a common and ‘easy’ technique to apply  There are a number of practical issues to consider Materials Handling Why is transportation an issue?  All production systems involve materials, machines and people  Need to bring these together - usually materials  Transportation:  Results is loss of control?  Component  <1%  transport time often negligible compared to queue time transport, 5% value add, 95% queue/wait time In manufacturing transportation does not add value  Added expense of equipment and people  Damage and safety issues  Customer does not see benefit Caution! “The earliest ideas on material handling centered about mechanical devices to assist persons doing the moving, i.e., mechanize the job. In general, this brought savings. But all too often plant engineers tended to instinctively to “put in a conveyor” to solve the handling problem when in many cases a conveyor was not the answer, any more than a universal answer of “use pallets and get a lift truck” is correct. Each type of handling device has use in its proper place.” Muther 1955 “Practical Layout Planning” Context of material handling  How important is it in design?  Primary  Ignore  concern? until end of design process? Handling is closely linked to:  layout design (i.e. positioning of machines)  macro design (i.e. cells, etc.)  For small discrete parts, in batch environment: not major influence  For large products and / or high volumes : it is important Example methods of transportation body body descends on chassis chassis low er mini Rover Mini production plastic tubing Diesel fuel injector nozzles compressed air manuf compts Kitting trolley U-shaped cells manuf compts assemble Selection of materials handling equipment Affected by many factors:  characteristics of material:  size  weight  shape  fragility  frequency of moves  distance to be covered  predictability of start and end points  production line  process based layout, etc. Intensity - distance plot Handling = short distance intensity of move Transportation = long distance Sophisticated handling equipment Sophisticated transportation equipment Simple handling equipment Simple transportation equipment distance Need models such as these to help understand where equipment is relevant and to understand differences ... Conveyors  Powered or unpowered  Continuous or intermittent  Provides point to point transport (does not move itself)  Can have accumulators for buffering, e.g. drinks industry  Bulk handling of powders - blow along pipes, e.g. flour transport  May be computer controlled  Belt, roller, etc.  Cross traffic possible  For flow layouts car door assembly car assembly line Transfer lines  Combined machines and transportation … flow layout  Used for transfer of parts - not that common now  Fixed material flow path  Dedicated to one production line - inflexible  Large and very expensive  Problems  machine breakdowns  maintenance  scrap products carry on through with further operations  upgrading difficult AGV’s - Automated Guided Vehicles work stations work stations Computer controlled Can be guided by rail, painted line or wire Collision detectors for safety Typically used in FMS (Flexible Manufacturing Systems) • however can be used to supply humans at work stations – ICL, Manchester: supply operators with computer components – Linn Products, Glasgow: supply operators with hi-fi components Allows some flexibility of start & end points Parts often transported with fixtures High initial investment Often becomes bottleneck in system • Is it appropriate (transport is non-value add)? • Simple check: is it always in use? warehouse Automated Storage and Retrieval Systems (ASRS)  Examples:  component stores        shoe shops?! Computer controlled Make maximum use of 3D space available Expensive to install and maintain Can encourage inventory (hides the problem) Enables accurate records of quantities? Warehouse may become Wherehouse? Cranes  EOT - electric overhead travelling cranes  Jib cranes - column mounted or free standing  Expensive to install and maintain  Can cause production delays while waiting  Introduces additional safety hazards  Tend to be fixed in one area  For heavy, bulky materials  Often used in functional layouts Trucks Fork lifts, trucks, carts, etc. Relatively cheap Extremely flexible Limited capacity Layout types • Functional & cellular power: gas, electric, petrol require wide aisles and turning areas? manual types do not necessarily need dedicated/skilled staff can have very high reach Robots Beneficial for • hazardous environments • arduous environments • accuracy • continuous operation Drawbacks • Expensive • Limited range Different types of power • Electric, hydraulic, pneumatic Easy to teach 1980’s - rise and fall? For flow layouts and cells Fixed Fixed series of robotic machining cells robot placing window Material handling in flowline systems Transporting - movement to, from and along the line Pacing - maintaining a steady and predicable output - e.g. cars Holding - presenting the work in the appropriate orientation Storing - providing temporary buffer between stations Indicators of poor material handling Safety problems Unclear flow patterns Lost parts High utilisation of material handling equipment Damage Unidentified material Production delays A related issue - Packaging  Transportation requires close link with packaging  Packaging used for:  Internal / external movement  Containment, Protection, Identification, Image  Big issue regarding waste, recycling, etc.  Can be consumed with the product (e.g. bag and contents supplied to customer both fed into manufacturing process)  Used for lot control  Lot control is were discrete item/product is assigned number and tracked  Assists in the manufacture of the product  Essential for quality control and tracing back • May not need packaging if supplied in bulk  e.g. polymer chips for blow moulding taken by tanker to silo Packaging - exploding variety Final assembly operations and packaging add to variety • Single base product becomes numerous variant products • Need to physically store each variant? • Often difficult to search across variants for specific sale (ie. Preferred item not available but substitute available?) Consequence of changes: increased cost due to • Additional labour (assembly, transportation, admin) • Wasted components / packaging variants Base Oven/Stove 3 Last assembly 15 Test 20 Pack 40 Despatch Store New packaging (e.g. customer labels) Different test spec (e.g. different, tighter) Different options (e.g. oven LPG not natural gas) Packaging - Pallets Very common in internal / external transportation, wide variety • Material - wood or plastic (important for food industry) • Physical properties (no one type of pallet) – Size (1100x1100, 1200x1000, etc) – Reversible, 2 way / 4 way Often dictated by customer • high variety leads to stock control issues – money / space required affected Example of pallet flow Pallet stored for customer X on 2 way pallet Needed for customer Y Reversed with slip sheet onto second pallet (happens to be 4 way) Shrink wrapped Loaded into container and pallet slipped off Other stages - not covered here  Steady state design  capacity analysis  designing  Dynamic design - advanced!  changes  things over time go wrong  Covered  for average conditions in 4th year Computer Modelling and Simulation Control system design - advanced!  Covered  How in 3rd year Manufacturing Operations Management class to control material flow between machines/operators