Copyright is owned by the Author of the thesis. Permission is given for a copy to be downloaded by an individual for the purpose of research and private study only. The thesis may not be reproduced elsewhere without the permission of the Author. Creation and Implementation of Customised Production Scheduling Software in a Processed Cheese Factory A thesis presented in partial fulfilment of the requirements for the degree of Master of Technology • ID Manufacturing and Industrial Technology at Massey University, Palmerston North, New Zealand Ross Aiken 2000 Abstract This project investigated creating computer algorithms and friendly sotiware interfaces to assist with the cheduling of single stage operations\\ ith equence dependant et-ups and ere\\ ro tering problems across multiple lines. Various techniques and approaches \\ere investigated for reducing the total solution pace including. grouping similar items and orders and bucket schedu ling. The principle of the Goldratt Method of Scheduling \\ere u ed A Tabu earch algorithm "as implemented to search for solut ions '' here total mal-e- pan ''as 111inim1 ed and probability of missing orders \\3S tal..en into account in an unreliable production System ,\ /1cro.,u/1 . lcce.\.1 and .\ ltcrli.\u/t I '1s11al Hosie 1\ ere used to create a stand alone application that interfaced\\ ith an Manufacturing Resource Plann111g s~ stcm Table of Contents A bstract ... . ..• 1 Table of Contents ... II Table of Figures ......... . ... . .. ... . . . .. . . ... .. ... . ... ... .. .. .. . .. .... . ... .. .... .... ... ... ... ........ . .. . . . . . . . . . . .. . .. . . .. . ...... VII Li st of Tables ......... ...... . ... .. ... ... .. . . . ... ... . .. ... . .... . ... . .. . .... .... . .. . . . .. ... .. . .. . . .. .. . ... .. .... .. .... ...... .. V III Chapter I - Introducti on .. . . ...... .... .. .......... ... V III I . I - Overview .............................. . . ... I .. .. .. .... ...... I I .2 - The Pro ject' s Spec ifi c Goals I 3 - Structure of thi s Report .. . ......... ... ...... ... ..... .. .. .. ... ... .. ... ..... ... ... ... .... . 2 I .4 - Introducti on to Pastoral Foods (NZ) L imi ted .. .., ..... .... .. ...... .... ... .. ..... .... . ... .) I .4 . I - Background to the eed fo r the Project ......... ... . .... 3 I 4 2 - Manu fac turing Fac iliti es and Products ...... 5 I .-U - The Scheduling Problem ....... ... .......... .... ..... ...... ... ........ ........ .... ........ .. . .... 7 I 5 - Schedulin g Jn New Zealand .. . ······· ... .... ... .... 9 Chapter 2 - Com puter Programrn in!..'. Svstems ....... ...... . . ... JO 2. I - Overview .. . ... ......... .... JO 2.2 - Database and Pro!..'.ramrni ng Svstern s .... .... ....... .. ..... .. .... .... ............ .. .. ......... .... .... .. I 0 2 3 - M RP-11 Svstems and Inter faces ...... . . JO Chapter 3 - Schedul ing Techniques and ystems .......... .... . .. . ............................ I I 3. I - Overview. .. I I 3.2 - Leve ls of Plannin !..'. .. ... ...... ..... .... ... ... ... ... ........... ... ..... .. .... ... .. .... .............. ... .. ....... I I 3.2. I - Overview ........................................... ... ............ .... ...... ........................ .. .. I I 3.2 2 - Long Range Forecasts and Rough Cut Capacity Planning . 3.2.3 - Master Production Scheduling . 12 .... I 2 3.2.4 - Shop Floor Control ................. . . ... ............ .. .... .. .. ... .... .. ...... ........ . I 3 3.3 - Simplification of Scheduling of Complex Processes 3.4 - Scheduling Objective Functions 3.5 - Sequencing ........... . .. ... I 5 ....... 16 . 19 3.6 - Sequence Dependant Set-U ps ........ ... ..... ........ .. ..... ...... ........ .. ..... ............... ... ....... . 20 3.6. I - Overview ............... . .. .... .. .. ...... .. .... ... .... ...... ... .... .. ..... .... .. .... ... .... ... .. .. .... ... 20 3.6.2 - Standard Sequence .............................. ..... ........... .... ................. .. ...... 2 I 3.6.3 - Conditional Standard Sequence ........... .. ... .. ... 2 I 3.6.4 - Trial and Error Calcu lated Sequence .. . . ................ 21 II 3.6.5 - Combinations of Sequencing Techniques .. .... . 3.7 - Grouping Simi lar Items 3.8 - Crew Rostering ............. ..... .. . ... 23 .... 23 ..... 25 3.9 - Time Management Techniques .. .. ........ . ... 26 3.9.1 - Overview .... ...................................... .. .. ................................. .... ......... 26 3.9.2 - Continuous Time Line Scheduling 3.9.3 - Bucket Scheduling ........... .. . 3.10 - Scheduling Svstems with MRP-11 . .... ........ . . ... 27 . ... 27 .. 29 3.10.1 -Overview .... . .. .. .... .... ..... . .. .. .......... ...... . ... 29 3.10.2 - Master Production Schedule Program .... .. .... ...... ... ... .. .... ... .......... . . .. 30 3. 11 - Schedu lin g Svstems without MRP-11 ..... 32 Chapter -+ - Multistage Schedu lin g Techniques . ..,.., .......... .... .... .) .) 4. I - Overview ..,.., .. . . .) .) 4.2 - Forecast Mvopic Di spatch Method .. ............ .. ........ .. ... .......... .... .... .... .... ......... ..... 33 4.3 - OPT / Goldratt Schedu ling Method ........................... .. . .. 34 Chapter 5 - Techniques in Searching fo r Solut ions .......... ..... ...................... . . ................... 35 5. I - Overview ..... ........... ........... . ............. ..................... . 35 5.1.1 - The Size of th e Prob lem ...... ... .. .... . . .... 35 5.1.2 - Techniques Avai lable . ... . 36 5. 1.3 - Effects of Sequence Dependan t Set- Ups .............. ...... . . ...... 36 5. 1.4 - Vis ibility Problems ... .. ... .. .... .. .... ..... ... ....... .. ......... ... .... .. ..... .... .... ....... .... 3 7 5.1.5 - Measuring Results ..... ..... ....... .... ......... ............ .. ... .... .... .... .. ..... ....... ... ..... 37 5.2 - Com plete Enumerat ion ........... . . ........ 38 5.3 - Branch and Bound ....... .40 5.4 - Random Pair-Wise Interchange .................... . . ...... .......... ..... .. ..... ..... .... .... .. .42 5.5 - Tabu Search ......... .. .. .. ...... ..................... .. .... .. ... ....... .. ... ....... ...... ....... .. .... 45 5.6 - Ind ividual Group Enumeration .......................... .... ........ ................... .. ..50 ...... 51 5.7 - Combination Individual Group Enumeration and Tabu Search Chapter 6 - Data Collection Methods .. . ........ ..... ... .. ... . ... .... ........ .... ..... ... .... .... .... ...... 53 6. l - Overview. . .. ..... ... .. .... ...... .. ... .. .... .. .... ... .. .... ....... .. ....... 53 6.2 - Collecting Production Rates v Machines .. ... ... ..... ...... ..... ... ........... .......... .. ... ..... .... 54 6.3 - Collecting Changeover Times ............... ......................... . . ..... ...... ....... .. ..... 55 Chapter 7 - [mmunity from Di sruption ......................... . . ..... .................. . 58 7.1 - Overview ....... ....... ..... .. .... .. ... ... .... ... .... ... .. ..... .. ...... .. ..... ... ... ...... ... ..... ..... ....... .. ... .... .. 58 111 7.2 - Shipping Buffers ... . .. 58 7.3 - Time and Space Buffers . . .. .. .. . 59 7.4 - Avo idin g Vulnerabilitv to Missing Orders ···· ····· ······· ···· ····· ····· ···· ·········· · .... 59 7.5 - Available to Promise .............. .... .... ... ... .... ... ..... .. . .... .... .... .. ...... ....... ........ .. .. ..... . .... 62 Chapter 8 - Raw Material Availabilitv. ................. ... .... .... ... . ... 63 Chapter 9 - Optimi sation Macros (A utomati c Solutions) . ..64 Chapter I 0 - Visual [nterfaces (Manual Solutions) ......... . 66 I 0. I - Overview ................ . .. 66 I 0 2 - Gantt Charts .. . .. ..... ... ... .. .. .. .. .. ............... ... ... ........ .... .. ......... .... ..... .. ....... 66 I 0.3 - Adjustable Summary Tab les .......................... . . 10.4 - Case Study - Use of Ad justable Summary Table Chapter I I - Over-All So lutions . .... 68 .... 71 .. 73 I I . I - Overview ............................... ... . . .. .... ... .... ...... ... .... .... ........ ...... ...... ... ........ 73 11 2 - Procedure of the Svstem·s Operat ion .... .... ............ .. ............. ..... 7-l I 1.2.1 - Obtain a Customer Order Listing .. . .... 75 11 .2.2 - Display Capacity Constrain ts and Restrictions for Each Bucket .. . .................. ... ... . ... 76 11 .2.3 - Adj ust Capacitv Constraints and Restrictions for Each Bucket ....... 77 11 .2.-l - Run the Automatic Schedule Optimisation Macro ....... ..... ........ ..... 77 11 2.5 - Inspect and Adjust Schedule .................. ... ..... ... .. ... .. .. 78 11 .2.6 - Check for Raw Material Avai lab ility ... . ... ....... 78 11 .2.7 - Adjust Schedule in Accordance with Raw Material Avail abi lity .............................................. . . ... .... ..... .. ... 79 11 .2.8 - Feed Back Exception Information .. ......... ..... .. ..... ... . ·· ··· ·· ·· ···· ···· ... . 79 11 .2.9 - Output the Schedule to Manufacturing ..... ...... ... .... ... ..... ... ... ... 79 11 .3 - Procedure for Accepting New Customer Orders . . .... 80 11 .3.1 - Obtain a List of Unmatched Customer Orders . . ... 80 11 .3.2 - Available to Promise Capacity Constraints and Restrictions .... 80 11 .3.3 - Decide what Extra Orders to Plan ...................................... ...... ... .... . 81 11.3.4 - Create Shop Orders and/or Firm Planned Orders for Orders ... . ... 81 I 1.4 - Coping with Changes in Requirements 11 .5 - Future Work ... . ..... .. ... .. ..... .. .. ......... .. .. .... 82 . ... 82 Chapter 12 - Discussion and Conc lusions ........ .... ....... ... ....... .... .... .. ..... ... ...... ...... .. .. .. ....... ... .... 85 12 . l - Overview .... .. ...... ....... ... .... ......... ....... ..... ... ... ..... .... .... ...... .. ........ ..... ....... ............... 85 JV 12.2 -Operators Vie\\· .................................................................................................... 86 12.3 - Outcomes for Pastoral Foods .......................................... ..................... .......... ...... 86 Append ix I - Pastoral Foods (NZ l Limited L ist of' Items ............ ............................................ 88 I . I - Individual!\ Wrapped Sl ices - Li st or Items .................. ... ......... ................ 88 1.2 - Slice on Slice - List or Items ....................................................... ......... ....... 91 1.3 - Cheez Toyz. Bodz - List of Items ................................................................ 9 1 1.-l - Cheese preads - Li st or Items .............................................................. 92 1.5 - Packets (250!..'.) - Li st of Items .................................................................... 92 1.6 - Blocks (20kgl - List of ltems ........................ ............................................ ... 92 1.7 - Blocks (2k!..'.l - Li st of Items ......................... ........................................ 9'.2 1.8 - Skins - List of Items .... ......... . ........ ..... ............................................ 92 1.9 - EnL\l11C Modified Cheese- List of ltems ............ ....................... ...... ........... 93 1.10 - Pastes and lurri es - Li st of Items . ... ..... .... ................. .. ...... 93 Append1-: 2 - SOL Statements of Constraints and Restrictions ..... . . .9-1 2. I - Spcciall\ Procc sed Cheese Depanment SOL Statement . ...... .......... ..... .... 9-1 Appcndi-: 3 - Trials. .. . . ........ ............ ........ .... ..... ... .. ............... ............... .. ..... 96 3 I - Procedures for Trials .. .. . ... . ... . . . . .. ... ... . .... ... . . .... .. . . ... ... ..... . ........ 96 3.1.1 - Procedure for Trials or cheduling Stratc!!.ies ................................. 96 3 1.2 - Procedure for Trials or Search fcchn1qucs .. ...... ........ .. 97 3 2 - Trial s Result~ - Strategics Against Sequence Dependant ct-ups 98 3.2.1 - Due Date Sequence On!\ .... .......... ......................... ... ..... .. . .. 98 3.2.2 - Batch Same Items ................................ .. .... ...................... ........ ..... .... .. 99 3 2 3 - Batch ame Formulations .................................................................. I 00 3.2.-1- Batch Same SiLes ................................................................................ IOI 3.2.5 - Batch ame Groups ..... .......... ........... .... ........ ........ .. ............ ............. ..... I 02 3.2.6 - Batch ame Odd Bal l Groups ............................................................ I 03 3.2.7 - Batch ame Group , Then Same Items ................................................ I 0-1 3.2.8 - Batch Same Groups. T hen Same Formulations ..... ..... ..... ..................... I 05 3.2.9 - Batch Same Groups. Then Same Sizes ......................................... .. ...... I 06 3.2. 10 - Batch Same Odd Ball Groups. Then Same Items ............................... I 07 3.2. 11 - Batch Same Odd Ba ll Groups. T hen Same Formul ations ............. .... . I 08 3.2.12 - Batch Same Odd Ball Groups. Then Same Sizes ................................ I 09 3.3 - Results of Trials of Search Techniques ........................................... ................... 110 3.3.1 - Branch and Bound ................................................................................. 110 v 3.3.2 - Random Pair-wise Interchange ............ .. ....... .................................... ..... I I I 3.3.3 - Tabu Search ....... ........... .......... .......... ................................ .. ........ .. ......... 11 2 3.3.4 - Combination Individual Group Complete Enumeration and Tabu Search ........ ..... ... ........... ........... .. ...... ... .. ............................... ............. ...... I 13 Appendi x 4 - Definitions of Terms Used ... ......................................................................... 11-l Bibliographv ................. ............... ................ .......... ............ ... ......... ... .. .......................... .......... I 18 VI Table of Figures Fi iw re I - Pas1orol Food~ Manufacturing Process ..................................................................... 6 Figure 2 - Crew Rostering Gan tt chart (Example ) ................................................................... 26 Figure 3 - Master Production Schedule Procedure ........ ...................... ..................................... 31 Figure -l - Procedure Flo\v Chart - Complete Enumeration ................ ............. ...................... 39 Figure 5 - Procedure Flo\.v Chart Branch and Bound Map .... ..... ................................ ....... 40 Figure 6 - Procedure Flo\v Chart - Branch and Bound ........... .............. .. ................................ -l I Fi gure 7 - Graph of Results - Branch and Bound ................................... ......... .. .. .. ... .. ..... .. .. -l2 Figure 8 - Procedure FIO\\ Chart - Random Pair-Wise Interchange......... .... .. .. .. . .. .... -l-l Figure 9 - Graph of Results - Pai r-Wi sc Interchange ...................... ... ..... ... ...... .... ..... . -l 5 Figure I 0 - Procedure Flo\v Chart - Tabu Search . ................. ................................ .... .. ...... .. -l 8 Fi !.!.ure I I - Graph of Results - Tabu earch ..................................................................... .. -l9 Figure 12 - Graph of Results - Individual Group Enumeration and Tabu Search ... . .. .. .. . . 51 Figure 13 - l'as1ornl Food,· SOS Product Characteri stics ................ ..... ... .... . Figure 1-l - l 1w 1ornl Food\· SOS Product Change Critical Path Diagram .. Figure 15 - Gantt chart Inter face - J1l/\10/'lll l·ood.1 IWS Department Fi!.!ure 16 - Gantt chart In ter face - l'ml