Operations Management - II Post Graduate Program Session 5. Vinay Kumar Kalakbandi Assistant Professor Operations & Systems Area

Transcription

1 Operations Management - II Post Graduate Program Session 5 Vinay Kumar Kalakbandi Assistant Professor Operations & Systems Area 1/25/2016 Vinay Kalakbandi 1 Agenda Recap onner company Recommendations Process Selection Facility layout planning Inventory Management - Basics 1/25/2016 Vinay Kalakbandi 2 1

2 onner Company Recommendations Tactical chances Operational changes Strategic changes 1/25/2016 Vinay Kalakbandi 3 PROCESS SEECTION 1/25/2016 Vinay Kalakbandi 4 2

3 1/25/2016 Vinay Kalakbandi 5 Process Selection eciding on the way production of goods or services will be organized When do you do it? Why is it important? 1/25/2016 Vinay Kalakbandi 6 3

4 Key factors Key factors that process selection depends on Volume of output Variety of output Other factors to consider Flexibility of equipment Flow of material 1/25/2016 Vinay Kalakbandi 7 Remember the evel of analysis? 1/25/2016 Vinay Kalakbandi 8 4

5 Arrange these in the decreasing order of Volume of output. 1/25/2016 Vinay Kalakbandi 9 o you have it? 1/25/2016 Vinay Kalakbandi 10 5

6 Arrange these in the increasing order of Variety of output. 1/25/2016 Vinay Kalakbandi 11 o you have it? 1/25/2016 Vinay Kalakbandi 12 6

7 Variety Not Competitive Observations? 1/25/2016 Vinay Kalakbandi 13 Too Expensive Volume 1/25/2016 Vinay Kalakbandi 14 7

8 Product Process Matrix 1/25/2016 Vinay Kalakbandi 15 Continuous flow Highly standardized goods and services Very efficient, very high volume Very rigid, lack of variety, costly to change, very high cost of downtime Usually continuous flow Equipment has very less flexibility 1/25/2016 Vinay Kalakbandi 16 8

9 Repetitive/Assembly Standardized goods or services ow per unit cost High volume, efficient Flexibility? Flow? 1/25/2016 Vinay Kalakbandi 17 Batch Process Semi-standardized goods and services Flexibility easy to add or change products or services Moderate cost per unit, moderate scheduling complexity 1/25/2016 Vinay Kalakbandi 18 9

10 Job Shop Customized Goods and Services Able to handle a wide variety of work Slow, high cost per unit, complex planning and scheduling Flexibility? Flow? 1/25/2016 Vinay Kalakbandi 19 ayout Planning ayout planning in manufacturing & service organisations deals with physical arrangement of various resources that are available in the system with an objective to improve the performance of the operating system Benefits of good layout design Jobs in a manufacturing system travel lesser distance Customers spend less time in service systems Costs & ead time come down Improved quality 10

11 Types of ayout Process ayout arrangement of resources on the basis of the process characteristics of the resources available Product ayout order in which the resources are placed follow exactly the visitation sequence dictated by a product Group Technology (GT) ayout seeks to exploit commonality in manufacturing and uses this as the basis for grouping components and resources Fixed Position ayout emphasis is not so much on optimum position of resources required for the process, since the product itself largely dictates this; the focus is on gaining better control of material flow and reducing delays Process ayout Product A Product B Product C M M M M G G G 11

12 Product ayout M G Product A G Product B M G Product C Group Technology ayout Cell 1 Cell 2 M M G G M G M Cell 4 Cell 3 12

13 Machines esign of GT ayout The objective is one of sub-dividing an universe of machines and components into sub-groups Each sub-group of components form a part family and is endowed with a corresponding sub-group of machines known as machine groups Each sub-group is referred to as a cell GT layout design is done with a systematic analysis of a machinecomponent incident matrix Number of methods available for identifying sub-groups Production Flow Analysis (PFA) Clustering techniques Matrix manipulation methods Graph theory Mathematical programming methods Machine Component Incident Matrix Components A B C E F G H I J

14 Machines Machine Component Incident Matrix Components B C A F E I G H J Fixed Position ayout 14

15 ayout esign - Performance Measures Performance Measure istance travelled by jobs in the shop floor Space utilization index Material Handling costs ead time of the processes Investment in work-in-progress Inter-departmental moves Utilisation of the resources Ease of production control Number of ownership changes Basis for measurement Kg - Metres of job movement for each product Minimum space required to actual space utilised Rupees per month Hours per average product Rupees per month Number and quantum of inter-departmental moves Percent to total capacity Number of job cards and control documents generated; Size of the progress chasing staff Number of times the responsibility for the job changes hands esign of Product ayout Several Mass Production Systems are in operation today Various sub-assemblies in a mass producer need to be configured to match the production rate Similarly, the final assembly stations also need to have the required number of resources at each station to meet the targeted demand A product layout design seeks to identify the minimum number of resources required to meet a targeted production rate and the order in which these resources are to be arranged Technique employed for designing of product layout is known as line balancing 15

16 ine Balancing ecisions and Tradeoffs ine balancing A method by which the tasks are optimally combined without violating precedence constraints and a certain number of workstations designed to complete the tasks Key decision variables are production rate, cycle time and the number of workstations, which are inter-related Solving the line balancing problem calls for striking the right trade-off between increased production and better utilisation of resources Cycle time is the ratio of the available time to the actual (desired) production rate ine Balancing Actual ( esired ) Cycle Time Actual AvailableTime ( esired ) Pr oduction Minimum No. of work stations required Sum of all task times Cycle Time Average Re source Sum of all task times Utilisation Number of workstations * Cycle time 16

17 Time (in seconds) Up Up C Power Systems The Current ayout TESTING FOR AC INING RACK R& RAW MATERIA STORAGE RACKS C RAW MATERIA STORAGE RACKS COI STORAGE ASSEMBY INE 3 FREIGHT IFT CABINET STORAGE ASSEMBY INE 2 SUBASSEMBY TABE CABINET STORAGE BOXING FINISHING STAGES C QC MATERIA STORAGE RACKS ASSEMBY INE 1 TEST BAY ARRAY IFT C Power Systems Task distribution Task times Cumm. Task time Cycle Time 0 Cycle time (TAKT time) 480 Secs Output Per day about 150 (ideal) Output Per day not more than 100 mostly 17

18 Up Up Issues with the Current System High number of stations: Sixteen stations - sixteen operators work on one work piece. Cumulative statistical fluctuation Operator fatigue due to excessive movement: Back and forth to the inventory racks ack of station discipline: Just fill the gaps Absenteeism: One operator effects 1/3 rd of the production ack of flexibility in the line: No Place to add more stations ack of teamwork and coordination: 16 is a crowd Spiky demand of Product Y: ack of Production control The Proposed layout TESTING FOR AC INING RACK R& RAW MATERIA STORAGE RACKS CABINET STORAGE CABINET STORAGE C RAW MATERIA STORAGE RACKS SUBASSEMBY TABE COI STORAGE FREIGHT IFT KIT MAKING WIP STORAGE BOXING FINISHING STAGES C QC TEST BAY ARRAY IFT 18

19 Alternative System Station 1 Station 2 Station 3 Station 4 Station 5 Cumm. Task times Cycle time Comparing the two systems Attribute Old ayout New ayout Throughput (ideal) Variability High ow Flexibility to change in process configuration No 3 stations could be added Manpower Material handling High ow Flexibility to change in demand ow High Teamwork and coordination 16 member teams 5 member teams Operator movement High ow Effect of absenteeism High ow Shop floor Inventory 50 units inventory Zero No. of Testing Bays required