Setup Cost Reduction and Supply Chain Coordination in Case of Asymmetric Information

Screening contracts are a common approach to solve supply chain coordination problems under asymmetric information. Previous research in this area shows that asymmetric information leads to supply chain coordination deficits. We extend the standard framework of lotsizing decisions under asymmetric information by allowing investments in setup cost reduction. We find that asymmetric information leads to an overinvestment in setup cost reduction. Yet, the overall effect on supply chain performance is ambiguous. We show that these results holds for a wide variety of investment functions.

Reduction of production cycle time by optimising production and non-production components of time in the metalworking industry: a case study

The production cycle (PC) time, as a very important economic indicator of freezing current assets, involves the time needed to manufacture a unit or a series of units, from putting them into production until they are put into storage; and yet it is rarely discussed in the literature, even though it should be also analysed and be made as short as possible. The goal of this article is to survey and control the methodology of reducing the PC time of components in the metalworking industry, grouped by factor analysis into the factors of production and non-production components, observed by a modified method of current observations, and viewed as a process whose effectiveness was monitored using control charts. The survey is based on data collected through 1,576 observations in a Serbian company that manufactures electrical and electronic equipment for motor vehicles. The 2012 results, when compared with those of 2011, indicate that the PC time is significantly reduced by 93 minutes, or by 28.53 per cent, and the manufacturing time by 46 minutes, or by 19.17 per cent. The results furnish empirical findings that provide insights into a number of managerial issues concerning investment decisions in product-specific cycle time improvements and reductions, together with process redesigns

Reduction of production cycle time by optimising production and non-production components of time in the metalworking industry: a case study

The production cycle (PC) time, as a very important economic indicator of freezing current assets, involves the time needed to manufacture a unit or a series of units, from putting them into production until they are put into storage; and yet it is rarely discussed in the literature, even though it should be also analysed and be made as short as possible. The goal of this article is to survey and control the methodology of reducing the PC time of components in the metalworking industry, grouped by factor analysis into the factors of production and non-production components, observed by a modified method of current observations, and viewed as a process whose effectiveness was monitored using control charts. The survey is based on data collected through 1,576 observations in a Serbian company that manufactures electrical and electronic equipment for motor vehicles. The 2012 results, when compared with those of 2011, indicate that the PC time is significantly reduced by 93 minutes, or by 28.53 per cent, and the manufacturing time by 46 minutes, or by 19.17 per cent. The results furnish empirical findings that provide insights into a number of managerial issues concerning investment decisions in product-specific cycle time improvements and reductions, together with process redesigns

Joint optimization of process improvement investments for supplier-buyer cooperative commerce

This research focuses on supporting the formation of strategic alliances through the concept of cooperative commerce, where suppliers and buyers work together to jointly optimize their businesses. The general goal of this research is to examine existing cooperative commerce models for obstacles that would hinder their successful implementation into modern industrial applications and to address those shortcomings. Total annual cost equations are formulated to capture the joint total relevant cost of cooperative commerce business relationships. These total joint relevant cost models will include terms that capture the ordering cost, holding cost, and cost of quality, as well as any applicable investment cost for process improvements, consistent with traditional economic order quantity and economic production quantity theory. This research corrects a modeling error of Affisco, et al. (2002) that led to underestimating the effectiveness of process improvements in joint economic lot size models. In addition, the models are expanded to accommodate a full range of product quality inspection policies, from zero to one hundred percent product inspections. Furthermore, the models are modified to account for the cost of scrap generation, as well as the effects of accepting non-conforming product and rejecting conforming product during quality inspections. Once the total cost models are expanded to account for these neglected costs, the joint total relevant cost equations are minimized to find the optimal batch sizes, and the effects of each model extension on the model solution are studied. Results indicate that these extensions do have a significant impact on the model results, such as reduced optimal batch sizes and increased optimal fraction conforming product

Implementação da metodologia SMED para a redução dos tempos de setup

Mestrado em Engenharia e Gestão IndustrialActualmente existe uma elevada concorrência nos mercados, originando nas empresas a necessidade de evoluírem para conseguirem sobreviver. Para além do aumento do número de concorrentes, os próprios consumidores mudaram, exigindo mais qualidade e maior variedade a um menor custo e em menos tempo. Com o intuito de melhorarem a sua produtividade, as suas relações com os clientes, a sua agilidade e os seus desperdícios, as empresas têm vindo a desenvolver novas técnicas ou usar técnicas já existentes, como é o caso do Single Minute Exchange of Die (SMED). Com este trabalho pretende-se mostrar a aplicabilidade do SMED em empresas produtoras de parafusos, rebites e peças especiais. Com base na revisão bibliográfica, onde se apresenta a fundamentação teórica desta metodologia, bem como outros trabalhos desta área, propõe-se um modelo para a implementação do SMED que, posteriormente, é colocado em prática na subsecção Dupla Pancada da Secção de estampagem da empresa 3Marcos. Os resultados da implementação deste modelo na empresa referida confirmam a aplicabilidade da metodologia SMED em empresas produtoras de parafusos, rebites e peças especiais, e, sobretudo, a sua eficiência para aumentar a competitividade dessas mesmas empresas. ABSTRACT: The current market competition forces companies to improve their processes in order to survive. Not only the number of competitors has increased but also the needs of the customers have changed, as now they demand more quality and more variety at lower costs and in less time. In order to improve their productivity, their relationship with customers, their agility and waste, companies have been developing new techniques or using existing ones, as it is the case of Single Minute Exchange of Die (SMED). The aim of this work is to show the applicability of SMED in companies producing screws, rivets and special pieces. Based on the literature review, where the theoretical concepts of this methodology are presented, as well as other works in the area, a model for the implementation of this methodology is presented and its implementation in the subsection Double Blow of the Stamping department of the company 3Marcos is described. The results of the implementation of this model in the referred company confirm the applicability of the methodology SMED in these types of companies and its efficiency to increase their competitiveness

Készletgazdálkodás és visszutas logisztika

A modern gazdaság egyre inkább szembesül a természetes erőforrások beszűkülésével. A meg nem újuló erőforrások készleteinek csökkenése a gazdaság szereplőit arra kényszeríti, hogy korlátozottan rendelkezésre álló ásványi anyagokat megkímélje. Ez a koncepció vezet a fenntartható fejlődés vállalati gazdálkodásba történő átültetésének szükségességéhez. A dolgozat célja a környezettudatos anyag- és készletgazdálkodás matematikai modelljeinek vizsgálata. A környezettudatos anyag- és készletgazdálkodást a magyar szakirodalomban az utóbbi időben nevezik visszutas logisztikának, inverz logisztikának, de néha hulladékkezelési logisztikának is. A magyar szóhasználat tehát nem egységes a terület megnevezésére. Angol elnevezése azonban meglehetősen egységes: „reverse logistics”. E kifejezésnek legtalálóbb magyar megfelelője talán a visszutas, esetleg reverz logisztika. A jelenleg is használt inverz logisztika kifejezést azért nem javasolt használni, mert annak angolul az „inverse logistics” felel meg, amit csak nagyon szűk körben – főleg Japánban - használnak a nemzetközi irodalomban, ezért fordítási zavart okozhat. Európában és az Egyesült Államokban a „reverse logistics” terjedt el. Így a terület magyar elnevezését a dolgozatban visszutas logisztikának választom

Modelling of Coordinating Production and Inventory Cycles in A Manufacturing Supply Chain Involving Reverse Logistics

In today’s global and competitive markets selling products at competitive prices, coordination of supply chain configuration, and environmental and ecological consciousness and responsibility become important issues for all companies around the world. The price of products is affected by costs, one of which is inventory cost. Inventory does not give any added value to products but must be kept in order to fulfill the customer demand in time. Therefore, this cost must be kept at the minimum level. In order to reduce the amount of inventory across a supply chain, coordination of decisions among all players in the chain is necessary. Coordination is needed not only for a two-level supply chain involving a manufacturer and its customers, but also for a complex supply chain of multiple tiers involving many players. With increasing attention being placed to environmental and ecological consciousness and responsibility, companies are keen to have a reverse supply chain where used products are collected and usable components remanufactured and reused in production to minimize negative impacts on the environment, adding further complexity to decision making across a supply chain. To deal with the above issues, this thesis proposes and develops the mathematical models and solution methods for coordinating the production inventory system in a complex manufacturing supply chain involving reverse logistics and multiple products. The supply chain consists of tier-2 suppliers for raw materials, tier-1 suppliers for parts, a manufacturer who manufactures and assembles parts into finished products, distributors, retailers and a third party who collects the used products and returns usable parts to the system. The models consider a limited contract period among all players, capacity constraints in transportation units and stochastic demand. The solution methods for solving the models are proposed based on decentralized, semi-centralized and centralized decision making processes. Numerical examples are used by adopting data from the literature to demonstrate, test, analyse and discuss the models. The results show that centralised decision making process is the best way to coordinate all players in the supply chain which minimise total cost of the supply chain as a whole. The results also show that the selection of the length of limited horizon/ contract period will be one of the main factors which will determine the type of coordination (decentralised, centralised or semi-centralised) among all players in the supply chain. We also found that the models developed can be viewed as generalised models for multi-level supply chain by examining the models using systems of different tiers from the literature. We conclude that the models are insensitive to changes of input parameters since percentage changes of the supply chain’s total cost are less than percentage changes of input parameters for the scenarios studied