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IENG 471 - Lecture 05

IENG 471 - Lecture 05. Group Technology – Production Flow Analysis. Assignments. Current Assignment: HW 3 See Assignment Link Complete spreadsheet modelling from the assignment link E-mail one spreadsheet model by 5:00 PM on the due date

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IENG 471 - Lecture 05

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  1. IENG 471 - Lecture 05 Group Technology – Production Flow Analysis IENG 471 Facilities Planning

  2. Assignments • Current Assignment: HW 3 See Assignment Link • Complete spreadsheet modelling from the assignment link • E-mail one spreadsheet model by 5:00 PM on the due date • Cover Page (1st tab on spreadsheet) has team names • New Assignment: HW 4 See Assignment Link • Download spreadsheet from the Group Technology II Linkon the Materials page – follow the steps for Kings’ Algorithm • Individual Assignment – can work together in groups, but each person turns in their own assignment • Electronically submit ONE spreadsheet with the final matrix (and typed solution) on a tab for each problem & a cover sheet tab • Highlight the family cells on the final matrix with highlighter tool • Interpret the final matrix of family cells – list which items compose each family, AND discuss how that affects the operation of the facility • Next Assignment: Prep for Exam IENG 471 Facilities Planning

  3. Volume, Variety & Automation Rembold, et. al. Transfer Line 100,000 10,000 1,000 100 1 Production Quantity High Medium Low Increasing Flexibility Batch Flow Line Increasing Productivity Flexible Mfg Sys Mfg Cell NC Machine 1 10 100 1,000 Low Medium High Part Variety IENG 471 Facilities Planning

  4. Layout Impact on Facility’s Machines • Job Shop Layout • Group by individual machines • Add all equipment fractions, then round up*, then add up actual space across the facility • Mass Production Layout • Group by individual products • Round up* all equipment fractions, then add up actual space • Cellular Layout • Group by similar part-process families • Add family equipment fractions, then round up*, then add up actual space across the facility * Multiply number of each machine type by footprint size after rounding to find the actual space required IENG 471 Facilities Planning

  5. Bulky, Difficult to Move Equip. (Precision fixtures) Bulky, Difficult to Move Prod. (Planes, ships, etc.) Layout Patterns Product Layout High Medium Product Volume Family / GT Cell Layout Process Layout Fixed Location Layout Low Low Medium High Product Variety Can Have Combinations (HYBRIDS)! IENG 471 Facilities Planning

  6. Examples • For the following situations, what type of General Layout would you suggest? • The assembly of bodies for GM midsize SUVs • Fabrication & Assembly of custom made sheet metal parts • Fabrication of computer cases for a line of desktop PCs, plus custom made sheet metal parts • Assembly of three distinct families of electronic cards for inkjet printers • Production of high quality, custom office furniture IENG 471 Facilities Planning

  7. Group Technology (GT) • Philosophy: • Use the similarity of current products to simplify the design and manufacturing of new products • Some Applications: • Identify and reuse similar process plans • Identify and reuse similar CNC programs • Identify the equipment that may be best used in a particular machine cell • Identify and eliminate redundant inventory • Requirement: • A taxonomyof part characteristics IENG 471 Facilities Planning

  8. Facilitates formation of part families and machine cells Quick retrieval of designs, drawings, & process plans Reduces design duplication Provides reliable workpiece statistics Facilitates accurate estimation of machine tool requirements and logical machine loadings Permits rationalization of tooling setups, reduces setup time, and reduces production throughput time Allows rationalization and improvement in tool design Aids production planning and scheduling procedures Improves cost estimation and facilitates cost accounting procedures Provides for better machine tool utilization and better use of tools, fixtures, & people Facilitates NC part programming. (Ham) Benefits of GT IENG 471 Facilities Planning

  9. How to Identify Groups • Similar Design Attributes • Size of parts • Geometric shape of parts • Materials • Technique: Parts Classification & Coding • Similar Manufacturing Attributes • Common processing steps (routings) • Common tools and fixtures • Technique: Production Flow Analysis • Similarity groupings are called Part Families IENG 471 Facilities Planning

  10. PFA Introduction • PFA is Production Flow Analysis • A subset of Group Technology (GT) • Goals: • Reduce material transport efforts • Reduce set up efforts • Reduce work in process inventory • Steps: • Identify OP-Codes for each Component • Routing/Process Planning information for each part • Incidence Matrix • Blocking (Triangularization) Algorithm • Cluster Identification IENG 471 Facilities Planning

  11. OP-Codes • An OP-Code forms an index to an Operation Plan • An Operation Plan is a generalized sequence of steps, perhaps common to multiple parts • An OP-Code Sequence is a method of condensing the Operation Plan into a compact structure suitable for data processing IENG 471 Facilities Planning

  12. OP CodeOperation Plan 01 Saw01 Cut to size 02 Lathe02 Face end Center drill Drill Ream Bore Turn straight Turn groove Chamfer Cut off Face Chamfer 03 Grind01 Grind 04 Insp06 Inspect dimension Inspect finish OP-Code Example Rotational Part (sectional view) IENG 471 Facilities Planning

  13. OP CodeOperation Plan 01 Saw01 Cut to size 02 Lathe02 Face end Center drill Drill Ream Bore Turn straight Turn groove Chamfer Cut off Face Chamfer 03 Grind01 Grind 04 Insp06 Inspect dimension Inspect finish OP Code Sequence 01 Saw01 02 Lathe02 03 Grind01 04 Insp06 OP-Code Example IENG 471 Facilities Planning

  14. Incidence Matrix • Rows represent OP-Codes(index = i) • Columns represent Components (index = j) • Cell Entries are: (M ij ) • 1 (or mark) - if the component requires the operation • 0 (or blank) - if the component does NOT require the operation IENG 471 Facilities Planning

  15. King’s Algorithm – Step 1 • Calculate the total (binary) weight of each column j: Wj =  2i Mij  i After Chang, Wysk, & Wang (1998) p.500 IENG 471 Facilities Planning

  16. King’s Algorithm – Step 2 • Sort the columns into rank order, then go to Step 3: IENG 471 Facilities Planning

  17. King’s Algorithm – Step 3 • Calculate the total (binary) weight of each row i: Wi =  2j Mij  j IENG 471 Facilities Planning

  18. King’s Algorithm – Step 4 • If all rows are in rank order STOP; otherwise, sort the rows into rank order, and then go to Step 1: IENG 471 Facilities Planning

  19. King’s Algorithm – Step 1 (2nd time) • Calculate the total (binary) weight of each column j: Wj =  2i Mij  i IENG 471 Facilities Planning

  20. King’s Algorithm – Step 2 (2nd time) • Sort the columns into rank order, then go to Step 3: IENG 471 Facilities Planning

  21. King’s Algorithm – Step 3 (2nd time) • Calculate the total (binary) weight of each row i: Wi =  2j Mij  j IENG 471 Facilities Planning

  22. King’s Algorithm – Step 4 (2nd time) • If all rows are in rank order STOP; otherwise, sort the rows into rank order, and then go to Step 1: IENG 471 Facilities Planning

  23. King’s Algorithm – Step 1 (3rd time) • Calculate the total (binary) weight of each column j: Wj =  2i Mij  i IENG 471 Facilities Planning

  24. King’s Algorithm – Step 2 (3rd time) • Sort the columns into rank order, then go to Step 3: NO CHANGE IN SORTED ORDER! IENG 471 Facilities Planning

  25. King’s Algorithm – Step 3 (3rd time) • Calculate the total (binary) weight of each row i: Wi =  2j Mij  j IENG 471 Facilities Planning

  26. King’s Algorithm – Step 4 (3rd time) • If all rows are in rank order STOP; otherwise, sort the rows into rank order, and then go to Step 1: SINCE THE ROWS WERE IN RANK ORDER, WE STOP! (yea!) IENG 471 Facilities Planning

  27. Partitioning • Ideally, the cells form mutually exclusive blocks (as below). These blocks define the Families: • Family A consists of Components A1, A3, A4, A5, A8, and A9; which can be machined in a cell performing Operations G05, L01, L02, and S01 • Family B consists of Components A0, A2, A6, and A7; which can be machined in a cell performing Operations D01, G06, M02, and M05 IENG 471 Facilities Planning

  28. Partitioning • Often, the cells do NOT form mutually exclusive blocks (as below). In this case, the capability for Operation G06 must be common to both machining cells: • Family A consists of Components A1, A3, A4, A5, A8, and A9; which can be machined in a cell performing Operations G05, G06, L01, L02, and S01 • Family B consists of Components A0, A2, A6, and A7; which can be machined in a cell performing Operations D01, G06, M02, and M05 IENG 471 Facilities Planning

  29. Strategies for Overlapping PFA Blocks: • Provide for transporting some components between cells requiring the overlapping operation(s) • Pick the component(s) with the smallest production volume(s) to transport to reduce handling costs • Locate the cells with operation overlap as near to each other as possible to reduce handling costs • Avoid scheduling concurrent production runs of the components that require overlapping operation(s) • Assumes that the equipment providing the overlapping capability can be easily moved between cells • This solution may improve capacity if the overlapping operation is a bottleneck • Put equipment capable of the overlapping operation(s) into each cell requiring it • Assumes the additional equipment capability is cost justifiable • This solution willimprove capacity if the overlapping operation is a bottleneck IENG 471 Facilities Planning

  30. Extended GT (PFA) • Requirements: • Need for grouping similar items together, and identifying separable items • Matrix of related entities: • Tooling • Equipment • Parts • Integrated Circuits • Modular Components • Solution Method: Triangularization • King’s Method • Direct Clustering Algorithm • Kusiak’s Triangularization Method • Ullman’s Design Structure Matrix IENG 471 Facilities Planning

  31. Relationship (Incidence) Matrix • Rows and Columns: • Parts requiring operations on different machines • Tools(in a CNC magazine) needed to produce part families • Departments requiring technicians (shared head count) • Departments requiring adjacent location • ICsrequiringmodularization • An entry in the incidence matrix means that there is a strong relationship between the row and column items IENG 471 Facilities Planning

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