The effect of engineering changes and demand uncertainty on MRP lot sizing: a case study

1985 ◽  
Vol 23 (2) ◽  
pp. 233-251 ◽  
Author(s):  
LUC G. CHALMET ◽  
MARC DE BODT ◽  
LUK VAN WASSENHOVE
Keyword(s):  
Demand Uncertainty ◽  
Lot Sizing ◽  
Engineering Changes

scholarly journals Dynamic lot sizing problem under uncertainty of returned products in remanufacturing industry

2018 ◽  
Vol 204 ◽  
pp. 07005
Author(s):  
Iman Setyoaji
Keyword(s):  
Bayesian Inference ◽  
Lot Sizing ◽  
Replacement Ratio ◽  
Total Cost ◽  
Lot Sizing Problem ◽  
Holding Cost ◽  
Dynamic Lot Sizing ◽  
Lot Sizes

Remanufacturing processes face uncertainty in the quality of the items being returned by customers, this significant variability complicates the control of inventories. Demands can be satisfied by procured new items, but also by remanufactured returned items. This paper develops dynamic lot sizing model for remanufacturing industry under uncertainty of returned items and proposes Bayesian Inference to estimate the replacement ratio of returned items that used to determine those lot sizes for new items. The objective of this paper is to minimize the total cost composed of holding cost and set-ups cost. A numerical example is provided based on case study. The result shows that total cost is reduced to be 45%.

Mean-Variance Model for the Build-Operate-Transfer Scheme Under Demand Uncertainty

2003 ◽  
Vol 1857 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Anthony Chen ◽  
Kitti Subprasom ◽  
Zhaowang Ji
Keyword(s):  
Demand Uncertainty ◽  
Network Design Problem ◽  
Transfer Scheme ◽  
Nondominated Solutions ◽  
Variance Model ◽  
Traffic Demand ◽  
Simulation Based ◽  
Capacity Selection ◽  
Mean Variance

A mean-variance model was developed for determining the optimal toll and capacity in a build-operate-transfer (BOT) roadway project subject to traffic demand uncertainty. This mean-variance model involves two objectives: maximizing mean profit and minimizing the variance (or standard deviation) of profit. The variance associated with profit is considered as a risk. Because maximizing expected profit and minimizing risk are often conflicting, there may not be a single best solution that can simultaneously optimize both objectives. Hence, it is necessary to explicitly consider this as a multiobjective problem so that a set of nondominated solutions can be generated. In this study, the optimal toll and capacity selection for the BOT problem under demand uncertainty is formulated as a special case of the stochastic network design problem. A simulation-based multiobjective genetic algorithm was developed to solve this stochastic bilevel mathematical programming formulation. Numerical results are also presented as a case study.

Style and substance: a case study of the expansion of mature business-to-business relationships in the Italian clothing industry

2017 ◽  
Vol 32 (1) ◽  
pp. 153-166 ◽  
Author(s):  
Mariachiara Colucci ◽  
Marco Visentin
Keyword(s):  
Demand Uncertainty ◽  
Clothing Industry ◽  
Business Relationships ◽  
Social Dimensions ◽  
Content Type ◽  
Relational Continuity ◽  
Business To Business ◽  
The Empirical Analysis

Purpose This paper aims to propose a model of the determinants of the expansion of mature business-to-business relationships in the downstream channel of the Italian clothing industry. The authors investigate the role of both economic and social determinants of retail buyers’ intentions to expand their relationships with a seller. Design/methodology/approach The empirical analysis is based on surveys of more than 150 retail buyers in mature relationships with a major clothing company. This context offers a unique opportunity to explore the interplay between the need for stable relationships and the need to continuously innovate to satisfy consumer demand, given rapidly changing tastes and styles, which can inhibit relationship expansion. Findings Buyers’ intentions to expand relationships are primarily determined by the absence of a formal agreement with the seller. Perceptions of a seller’s goodwill seem to overshadow the detrimental effects of two likely sources of opportunism in the clothing industry: demand uncertainty and the availability of alternative suppliers. Findings also provide evidence of a substitutive effect of formal control and trust in mature business relationships. Originality/value The authors provide insights into the dynamics of mature business relationships with a focus on expansion, rather than just the propensity for relational continuity, and they show how the interplay of transaction costs and social dimensions leads to this expansion. The authors also provide empirical evidence of a context, the clothing industry, where downstream relationships represent an important source of competitive advantage.

Matching volatile demand with transportation services in Vietnam

2015 ◽  
Vol 28 (1) ◽  
pp. 160-174 ◽  
Author(s):  
Albert Tan ◽  
Olli-Pekka Hilmola ◽  
Do Huy Binh
Keyword(s):  
Distribution System ◽  
Demand Uncertainty ◽  
Single Case ◽  
Night Shift ◽  
Research Work ◽  
Service Level ◽  
System Perspective ◽  
Content Type ◽  
Logistics Service

Purpose – Demand for retail transportation is typically volatile, and it is driven by the end of period (month) spiky deliveries. This is especially the case in emerging markets. The purpose of this paper is to examine situation in one of the leading Vietnamese logistics service company with numerous customers within the area of Ho Chi Minh City. Design/methodology/approach – Research work is based on a case study within a company called Gemadept, who is providing logistics services in Vietnam. Researchers were given access to the company data on distribution system, and the authors had collected daily data from transportation operations. Findings – Considerable truck utilization can be achieved even with volatile retail demand environment if optimization is applied to allocate trucks and drivers on certain routes and customer demand points. Relaxing service level of customers shall improve situation further, but not significantly. However, from logistics service point of view, it would be best to use numerous shifts per day (night shift option) to distribute products – this would enable high utilization of distribution fleet while overcoming spiky demand. Research limitations/implications – Analyses are dependent on a single case study of one logistics service provider in Vietnam. While this may limit the findings to some extent, but with rich case data and observations within the company distribution system, it provides the required depth to build an optimized model for the company. Practical implications – In volatile demand environment, it is important to allocate trucks and drivers as well as work schedule in a systematic order, and not based on trial-and-error human intervened timetable. System perspective also enables evaluation of different strategies and their implications on performance. Originality/value – Research work represents one of the seminal studies of Vietnamese retail logistics sector, and verifies that demand uncertainty is high in such environment in addition to exhibiting the end of period demand spikes (hockey stick effect).

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