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We introduce an original concept of the backroom effect for perishable products when the deterioration rate in a backroom is lower than that on retail shelves. With IoT-generated real-time informat...

This paper studies the influence of the demand-supply environment on the capacity scheduling performance of the logistics service supply chain. According to the key characteristics of the demand-su ...

Acquisition of cores is important for the success of remanufacturing business, but evaluating the value of cores is difficult due to many uncertain issues in the remanufacturing system. In this pap ...

Seamless steel tubes often have various categories and specifications, which further require complicated operations in production, especially in the cold treating process (CTP). This paper investigates the scheduling problem using the seamless tube plant of Baoshan Iron and Steel Complex as a study background. By considering the practical production constraints such as sequence-dependent setup times, maintenance schedule, intermediate material buffers, job-machine matches, we formulate the hybrid flowshop scheduling problem with a non-linear mixed integer programming model (NMIP). In addition, our model provides a flexibility to remove the permutation assumption, which is often a limitation in early studies. In order to obtain the solution of the above NMIP problem, a two-stage heuristic algorithm is proposed and it combines a modified genetic algorithm and a local search method. With real production instances, our computation experiments indicate that the proposed algorithm is efficient and it outperform...

In recent years, remanufacturing has emerged in various industrial sectors, and it adds an additional production alternative apart from the conventional manufacturing process. With remanufacturing, a used return product is often disassembled, reprocessed, and then reassembled into a new product. The remanufactured product is often of the same quality as those from regular manufacturing. Even though remanufacturing saves a substantial cost of materials, it often requires more labour and other inputs. Thus, it becomes important to examine the expanded production opportunity of the system. In this paper, we therefore make a first attempt to model such a system with respect to its optimal production. This model is based on the Cobb-Douglas (Wicksell) production function. More specifically, we focus on how labour costs, material costs, and the budget influence optimal production decisions. Explicit properties of the optimal plan are derived and presented as theorems. Results of this study are intended to provide a guideline for managers to make sound decisions, when dealing with the increasingly important remanufacturing systems.

In recent years, remanufacturing has emerged as an important research area. This requires developing methods and models in order to aid companies in systematically evaluating current as well as projected remanufacturing systems. This paper addresses the inventory control problem in a hybrid inventory system with manufacturing and remanufacturing options. In this study, by changing the definition of inventory position of the serviceable stock, we introduce a shift PULL inventory control policy, which is compared with PULL, DUAL, and Separate PULL control policies studied previously in the literature. Besides evaluating the economic consequences with different control policies, we also study system dynamic behaviour such as the bullwhip effect, in order to understand the advantages and disadvantages of different policies. After the experiments, we propose several management guidelines for such a hybrid inventory system. The major findings are: (1) separate PULL and DUAL can be good alternatives when the man...

A combined manufacturing/remanufacturing system is modelled and its dynamic behaviour is investigated using a control engineering approach. The model is an extension of the automated pipeline, inventory and order based production control system (APIOBPCS), which is well understood from a dynamic perspective. It is assumed that the remanufacturing process is based on a PUSH policy. Utilising different levels of information transparency from the remanufacturing process, three system types are developed and compared. Mathematical and simulation analyses of the system types were undertaken and their robustness to remanufacturing process uncertainties were tested. Our analysis indicates that the greater the degree of information transparency, the greater the robustness of the hybrid system.

A model to deal with the disassembly processes in remanufacturing systems is presented with focus being on evaluating their economic consequences. More specifically, the model assists decisions suc ...

Stochastic properties of a multi-period production-inventory system have been studied in several papers by applying the Laplace transform. However, the source of uncertainty has been limited to external demand and the production/replenishment lead time has been assumed to be constant. In this paper, we investigate the situation when the lead time is a random variable. Transform methods are again used to capture the stochastic properties of the system, such as stockout functions. With the objective of maximizing the net present value of the cash flow, we derive conditions for optimal production decisions in this system. The properties of cash outflow due to stockouts will also be discussed.

Input-Output Analysis, together with the Laplace transform, have been applied to multi-level, multi-period production-inventory systems in a number of papers. This article gives a historical overview of the areas involved in these studies. It is shown that the input and output matrices as well as the Leontief inverse can be generalised to include timing properties for the inputs by means of the Laplace transform. The consequent advantages are exemplified in different production models, treating, for instance, capacity requirements and safety stock problems. The main literature in this field concerns assembly systems, but the approach is easily applicable to process industries with a divergent material flow or when feedback is essential.