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This paper investigates the impact of import competition on energy efficiency among firms in China. Using a difference-in-differences approach that exploits industry- and firm-level tariff reductions following China's accession to the WTO, we examine the effects of reduced output tariffs on coal intensity, measured as coal use per output, of Chinese manufacturing firms. Our findings indicate that higher levels of import competition lead to significant reductions in coal intensity, without negatively affecting firm production levels. We also find evidence that these effects are primarily driven by multi-product firms adjusting their product mix to prioritize energy-saving options. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of separating the affiliated businesses from rail operations and the associated efficiency gain on firms' exporting decisions by rail. First, an economic model was built to analytically show that an efficiency improvement in rail operations would increase the firm's product variety but decreases the skewness of export by rail. The paper then utilized China's rail reform to separate the affiliated businesses from the rail sector in 2003 as a quasi-natural experiment and adopted the difference-in-differences (DID) method to empirically verify and quantify the analytical findings. Specifically, it is found the reform to separate the affiliated businesses significantly improved the efficiency of China's rail operations. The resultant efficiency gain then encouraged firms to export by rail, with more variety of export products and higher value. More importantly, the firm's skewness of export by rail has also been reduced. The relevant policy implications have also been provided. • This paper considers China's rail reform to separate the affiliated businesses from the rail sector in 2003. • We examine the effects of the reform on the efficiency of rail operations and the product mix of export by rail. • We find that the reform improved the efficiency of China's rail operations. • Firms' skewness of export by rail was reduced by the reform. [ABSTRACT FROM AUTHOR]

Agricultural producer organisations, the entities which aim at grouping farmers together, have become increasingly important in the food supply chain. In addition, they are widely viewed as having the potential to considerably contribute to rural people's wellbeing. Yet, we have only a limited understanding of the way in which these collective action organisations operate on the market. In response to this, the paper makes two contributions. First, our research documents an enormous variety in market behaviour of these organisations. This concerns both the product mix they offer and marketing channels they use. Second, drawing on recent advancements in theories of the firm, our analysis seeks to provide some insights on the nature and determinants of this heterogeneity. While the evidence we provide reflects merely conditional correlations, it points to two interesting regularities. On the one hand, it suggests that supplying large retail chains is positively associated with the organisations' size and openness to accept deliveries from non-members. On the other hand, it suggests that organisations operating in a more competitive environment offer less products than organisations that face lower pressure from the competition. Our specific example comes from the fruit and vegetable sector in Poland, a country which is among the biggest fruit and vegetable producers in the European Union. • We have only a limited understanding of the way in which agricultural producer organisations (POs) operate on the market. • Our research documents an enormous variety in market behaviour of POs. • POs under study are often multiproduct organisations that combine simultaneously different marketing channels. • POs supplying retail chains seem to be larger and more open to accept deliveries from non-members than other POs. • POs operating in a more competitive environment offer less products than POs that face lower pressure from the competition. • Our example comes from the fruit and vegetable sector in Poland, one of the biggest fruit and vegetable producers in the EU. [ABSTRACT FROM AUTHOR]

During the years, number of authors have argued against of possible non-optimality of throughput accounting product mix preference. Lastly, Linhares (2009) criticized throughput accounting heuristics in expanded product mix selection of Blackstone (2001). It is shown in this work that throughput accounting still outperforms any other approach in this referred hypothetical situation, if overall capacity availability of a constraint resource and total throughput per week delivered are being considered (vs. only using throughput per minute of a product). It is critical to expand own point of view to the profit of a system, instead of solely justify decisions on shorter time units, which are not the same with the decision period. However, as we illustrate further, throughput accounting has still its caveats, which arise especially from step-wise increasing operating expenses or from the requirement of integer product mixes. These could be addressed properly by analyzing situation as illustrated in this research work, or alternatively using expert systems concerning customers and operations optimization. Impacts of these actions on short-term profitability are significant. [ABSTRACT FROM AUTHOR]

One of the most challenging tasks for any industrial firm with a large product mix is the creation of a robust production schedule. In addition, it is not an unusual practice that last minute orders arriving with higher priorities will necessitate modifications to the existing schedule. The validity check of the production schedule is an important step, as it will affect the production plan, the allocation of resources, and may have a direct influence on the cost of subsequent setups. In this article, we introduce a discrete event simulation approach to obtain a reliable and fast scheduling analysis. The proposed methodology will evaluate the credibility of the generated schedule by measuring resources utilization, identifying bottlenecks, throughput, and evaluating the impact of each item in the product mix on these performance measures. The model will then highlight potential changes to the product mix and resources allocation as needed. The purpose of this research is to offer researchers a reliable and flexible approach to evaluate validity of modifications to production schedule. First, a parametric simulation model concept is introduced, and then the simulation results and analysis for a case study are presented. The proposed methodology was successfully applied to three production facilities at a major pharmaceutical company in Jordan. Monthly schedules at these facilities were analysed and the ability to meet production requirements were evaluated. Simulation results highlighted necessary changes to schedule and resources. [ABSTRACT FROM AUTHOR]

Theory of constraints (TOC) has emerged as an effective management philosophy suggesting practical solutions to various complex problems including product mix problem. Scholars have shown the superiority of various optimization (and artificial intelligence) approaches over the TOC-based heuristic to a “static” product mix problem, but have failed to see TOC as a whole, i.e. to take into consideration the impact of resource inter-dependencies, feedback loops, and importantly, statistical fluctuations ever present in any dynamic business environment. We proposed a system dynamics (SD) based simulation model to investigate product-mix problem under stochastic demand and scrap rates. We analyzed various scenarios by employing the drum-buffer-rope approach and constraint focused systematic scrap rate reduction approach, and importantly, evaluating performance using throughput accounting based global measures such as throughput and inventory. We conclude this paper by suggesting that future research efforts should be directed to develop an enabling hybrid expert simulation system to learn fundamental and powerful concepts underlying the theory of constraints. [ABSTRACT FROM AUTHOR]

Product mix influences the performance of pull production control strategy in multi-product manufacturing systems. The complexity of product mix on the performance of a manufacturing system is primarily based on the characteristics of the demand and production control strategies. Demands are mainly characterised by volume and product-type while production control strategy is characterised by material release time, part flow, inventory control and throughput times. In multi-product systems, pull production control strategy operates dedicated or shared Kanban allocation policy. This paper examines the performance of the Generalised Kanban Control Strategy (GKCS), Extended Kanban Control Strategy (EKCS) and Basestock Kanban-CONWIP (BK-CONWIP) control strategy operating Shared Kanban Allocation Policies (S-KAP) or Dedicated Kanban Allocation Policies (D-KAP) for a healthcare parallel/serial assembly line with setup times. A simulation based multi-objective optimisation technique was adopted to examine the effect of different product mixes on the strategies and policies. A ranking and selection technique for multiple systems was used to screen the performance of the strategies. It was shown that product mix variability in a system influence the inventory levels of the pull control strategies examined. However, the performances of the strategies vary with strategies operating S-KAP having better inventory control than strategies operating D-KAP. Similarly, BK-CONWIP outperformed its alternatives. [ABSTRACT FROM AUTHOR]

Abstract: In the real world of production, there are some uncertain parameters such as capacity, profit, and processing time. On the other hand, the fuzzy sets theory is applied as a suitable tool for managing production where dynamicity of the production environment prevents from determining target function, constraints and other parameters of the model. In this paper, a genetic algorithm embedded in fuzzy revised theory of constraints is presented for product mix problems. Results of implementing the proposed algorithm show efficiency and flexibility of this algorithm. [Copyright &y& Elsevier]

Abstract: The integrated product mix-outsourcing optimization is a major problem in manufacturing enterprise. Generally, heuristic or meta-heuristic solution approaches are used to optimize such problems. Heuristic approaches for these problems include Theory of Constraints (TOC) and Standard Accounting. Sometimes heuristic approaches are inefficient especially in large problems and instead, in these cases meta-heuristic algorithms have been applied extensively. In this paper a novel meta-heuristic algorithm “Imperialist Competitive Algorithm” (ICA) is applied to solve the integrated product mix-outsourcing optimization problem. Also, the results obtained from ICA are compared with the results of TOC and Standard Accounting approaches. [ABSTRACT FROM AUTHOR]

Abstract: This paper addresses the short-term capacity planning problem in a make-to-order (MTO) operation environment. A mathematical model is presented to aid an operations manager in an MTO environment to select a set of potential customer orders to maximize the operational profit such that all the selected orders are fulfilled by their deadline. With a given capacity limit on each source for each resource type, solving this model leads to an optimal capacity plan as required for the selected orders over a given (finite) planning horizon. The proposed model considers regular time, overtime, and outsourcing as the sources for each resource type. By applying this model to a small MTO operation, this paper demonstrates a contrast between maximal capacity utilization and optimal operational profit. [Copyright &y& Elsevier]