by Ha Yiu Cheung, Albert. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1988. / Bibliography: leaves 90-94.

Yip Ka-yun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 107-113). / Abstract also in Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Our Contributions --- p.2 / Chapter 1.3 --- Organization of the Thesis --- p.4 / Chapter Chapter 2 --- Literature Review --- p.5 / Chapter 2.1 --- Overview --- p.5 / Chapter 2.2 --- Research in Capacitated Lot Sizing Problem without significant setup times --- p.5 / Chapter 2.3 --- Research in Capacitated Lot Sizing Problem with setup time consideration --- p.12 / Chapter 2.4 --- Summary --- p.15 / Chapter Chapter 3 --- Capacitated Lot Sizing Problem with Setup Times --- p.16 / Chapter 3.1 --- Overview --- p.16 / Chapter 3.2 --- Problem Description and Formulation --- p.20 / Chapter 3.2.1 --- Our problem formulation / Chapter 3.2.2 --- Comparison between our problem formulation and traditional problem formulation / Chapter 3.3 --- Description of the Algorithm --- p.26 / Chapter 3.3.1 --- Wagner-Whitin algorithm / Chapter 3.3.2 --- Transportation problem / Chapter 3.3.3 --- Consistence test / Chapter 3.3.4 --- Subgradient optimization / Chapter 3.3.5 --- Computation of lower bound / Chapter 3.4 --- Design of Experiment --- p.43 / Chapter 3.4.1 --- Product demands / Chapter 3.4.2 --- Setup costs / Chapter 3.4.3 --- Setup times / Chapter 3.4.4 --- Capacity costs / Chapter 3.4.5 --- Inventory holding costs / Chapter 3.4.6 --- Quantity of capacity available for production / Chapter 3.4.7 --- Capacity absorption rate / Chapter 3.4.8 --- Generation of larger problems / Chapter 3.4.9 --- Initialization of Lagrangean multipliers / Chapter 3.4.10 --- Close test / Chapter 3.5 --- Open test --- p.58 / Chapter 3.6 --- Managerial Implications --- p.61 / Chapter 3.7 --- Summary --- p.61 / Chapter Chapter 4 --- Capacitated Lot Sizing Problem without Setup Times --- p.63 / Chapter 4.1 --- Overview --- p.63 / Chapter 4.2 --- Problem Description and Formulation --- p.64 / Chapter 4.3 --- Description of the Algorithm --- p.67 / Chapter 4.3.1 --- Decomposition scheme / Chapter 4.3.2 --- Wagner-Whitin algorithm / Chapter 4.3.3 --- Transportation problem / Chapter 4.3.4 --- Subgradient optimization / Chapter 4.3.5 --- Computation of lower bound / Chapter 4.4 --- Design of Experiment --- p.80 / Chapter 4.4.1 --- Product demands / Chapter 4.4.2 --- Setup costs / Chapter 4.4.3 --- Capacity costs / Chapter 4.4.4 --- Inventory holding costs / Chapter 4.4.5 --- Quantity of capacity available for production / Chapter 4.4.6 --- Capacity absorption rate / Chapter 4.4.7 --- Generation of larger problems / Chapter 4.4.8 --- Initialization of Lagrangean multipliers / Chapter 4.4.9 --- Selection of the extent of geometrical reduction and exponential smoothing / Chapter 4.4.10 --- Close test / Chapter 4.5 --- Open test --- p.92 / Chapter 4.6 --- Managerial Implications --- p.95 / Chapter 4.7 --- Comparison with other approaches --- p.96 / Chapter 4.7.1 --- Gilbert and Madan's approach / Chapter 4.7.2 --- Our algorithm for CLS problem with setup time consideration / Chapter 4.8 --- Summary --- p.102 / Chapter Chapter 5 --- Conclusion --- p.104 / Appendix A Vogel's approximation method --- p.106 / Bibliography --- p.107

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 198-208). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 198-208). Also available on the Internet.

No description available.

Materials requirements planning (MRP) is a widely used method for production planning and scheduling. Planned lead-time (PLT) and lot size are two of the input parameters for MRP systems, which determine planned order release dates. Presently, planned lead-time and lot size are estimated using independent methodologies. No existing PLT estimation methods consider factors such as machine breakdown, scrap-rate, etc. Moreover, they do not consider the capacity of a shop, which changes dynamically, because the available capacity at any given time is determined by the loading of the shop at that time. The absence of such factors in calculations leads to a huge lead-time difference between the actual lead-time and PLT, i.e., lead-time error. Altering the size of a lot will have an effect not only on the lead-time of that lot but also on that of other lots. The estimation of lot size and lead-time using independent methodologies currently does not completely capture the inter-dependent nature of lead-time and lot size. In this research, a lot-sizing model is modified in such a way that it minimizes the combination of setup cost, holding cost and work-in-process cost. This proposed approach embeds an optimization routine, which is based on dynamic programming on a manufacturing system model, which is based on open queuing network theory. Then, it optimizes lot size by using realistic estimates of WIP and the lead-time of different lots simultaneously for single-product, single-level bills of material. Experiments are conducted to compare the performance of the production plans generated by applying both conventional and the proposed methods. The results show that the proposed method has great potential and it can save up to 38% of total cost and minimize lead-time error up to 72%. / Master of Science

Synsam started the Synsam Group's Production and Innovation Center (SPIC) on Frösön in the summer of 2022 as part of their sustainability work. The factory locating in Sweden contributes to shorter lead times, reduced carbon footprint, and more environmentally friendly transportation. Synsam has its own collections, called \textit{House Brands}, where some are produced at the newly established production facility in Sweden, while others are outsourced for production in Asia. The outsourced production has longer lead time compared to the SPIC-flow, larger minimum order quantities, and greater risks in transport delays. The aim of the project was to compare production at SPIC, with the purchasing process from Asia, the Asia-flow. This to investigate the challenges and opportunities posed by establishing in Sweden, particularly concerning costs, risk, and logistics. The focus was on how the two flows tie up capital in finished goods inventory and inventory for components and materials, as well as the size of inventory holding costs. With the aim as a starting point, the project's first phase was initiated: a preliminary study with a literature review and informal interviews. Subsequently, the second and third phases involved data collection and processing. The fourth phase involved modeling, where optimization of the procurement and production processes was carried out entailed on selected parameters. Lastly, the fifth phase involved scenario analysis. Throughout all phases, verification and validation have been conducted. The project's conclusion shows that product groupings where the products are expensive or have low demand tie up less capital in the SPIC-flow compared to the Asia-flow. This is mainly because SPIC can produce smaller batches, thereby reducing the number of products in inventory since production can be more precisely aligned with demand. Another conclusion from the project is that in the event of a sudden decreased demand, the SPIC-flow has fewer products that need to be recycled compared to the Asia-flow, resulting in less capital tied up. The work concludes by presenting recommendations and suggestions for further work.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Aim: The purpose of this study is to present and test an algorithm that gives acceptable solutions in the optimization of a dedicated production line consisting of several machines, with regards of inventory holding cost and available capacity. The aim is also to suggest possible improvements in the practical case that has been used to test the model, which have been made in cooperation with Sandvik Materials Technology and it’s product unit Rock Drill Steel, located in Sandviken, Sweden. Method: An algorithm has been elaborated from articles and science reports and has then been tested with data from the practical case. The result has then been evaluated through an analysis where the algorithm’s ability to acceptable solutions and show potential savings with regards to capital tied up in stock of finished products, safety stock and products in work in process. Results and conclusions: The study shows that the algorithm has the ability to create acceptable solutions when given a specific demand rate, cycle time and capacity. The study also shows potential savings when using a shorter production cycle, given that the unit works in a structured way in order to shorten the production cycle. Suggestions for future research: The algorithm tested in this study needs more evaluations regarding its limits and possible benefits through practical and theoretical case studies. Contributions: The algorithm the possibility to combine principles and models aimed at solving the ELSP (Economic Lot Schedule Problem) and the principles of Schedule Leveling, which is a common term in lean production to a model that optimize inventory holding costs. These theories have similar approaches to cyclic production, but have different aims. Key words: cyclic scheduling, ELSP, economic lot size problem, schedule leveling, heijunka, lean production / Titel: Optimering och balansering av cyklisk produktion - en studie på Sandvik Materials Technology PU Borrstål Nivå: C-uppsats i ämnet Industriell Ekonomi Författare: Tommy Hedlund, Daniel Kvarnlöf Handledare: Mohammad Abid Datum: 2016 - Mars Syfte: Studiens syfte är att presentera och testa en algoritm som ger godkända resultat vid optimering av en dedikerad produktionslina bestående av flera produktionsresurser, med avseende på lagerhållningskostnad i omsättningslager samt tillgänglig kapacitet, samt att presentera möjliga förbättringsförslag utifrån de resultat som ges i det praktiska fall som simuleringsmodellen utvärderas genom. Det praktiska fallet i denna studie är Sandvik Materials Technology och dess produktenhet Borrstål. Metod: Studien har genomförts genom att en algoritm har tagits fram utifrån artiklar och forskningsrapporter på området, som sedan har prövats mot studiens praktiska fall. Resultatet har sedan utvärderats genom en analys av algoritmens förmåga att ge godkända lösningar, samt möjlig besparingspotential i det aktuella fallet utifrån kapitalbindning i omsättningslager, säkerhetslager och produkter i arbete. Resultat & slutsats: Studien visar att algoritmen har en god förmåga att skapa godkända resultat utifrån en specifik efterfrågan, cykeltid och kapacitet. Studien visar även på stora potentiella besparingar i kapitalbindning till följd av kortare cykeltid i såväl omsättningslager, säkerhetslager och produkter i arbete, givet att produktenheten arbetar strukturerat med att söka minska cykeltiden. Förslag till fortsatt forskning: Algoritmen behöver ytterligare forskning kring dess begränsningar genom att utvärderas utifrån fler praktiska och teoretiska fall. Uppsatsens bidrag: Algoritmen visar på en möjlighet att kombinera ELSP (economic lot scheduling problem) och dess modeller med de principer som återfinns inom Schedule Leveling, som är ett vanligt begrepp inom lean production. Dessa teorier liknar varandra men har till viss del skilda syften, vilka kan kombineras till en modell som optimerar produktionen med avseende på lagerhållningskostnaderna.

published_or_final_version / abstract / Industrial and Manufacturing Systems Engineering / Master / Master of Philosophy