Dynamic lot sizing problem with continuous-time Markovian production cost

In order to explore the autonomous incentive mechanism of platform-based e-commerce to online retailers' products, a product quality incentive model based on deposit and commission management is established for single retailer single quality products, single retailer products at multiple quality levels and double-retailer different quality products in three cases. Comparative analysis of the equilibrium results in three cases reveals that the effectiveness of the incentive mechanism of platform discount in the first case depends on the deposit strategy of the platform and the influence of the unit cost of excellent and low-quality products. In the second case, the incentive mechanism of platform discount is completely effective. The platform price discount has a positive incentive effect on retailers. The online retailers' increasing the sales of high-quality products and reducing the sales of low-quality products improve the high-quality product rate in the market. In the third case, the effectiveness of the platform discount incentive mechanism is mainly affected by the unit cost of products.

One of the factors to increase the competitiveness is the price of product. One of the factors that affect the product price is inventory cost. Shortages inventory can result in the cessation of the production process so that inventory is one of crucial issue in the company's operation while overstock had an effect on high costs. This research aimed to obtain integrated inventory model between products and packaging materials to minimize the total cost of inventory at PT Indomex Dwijaya Lestari considering safety stock. Data used in this research are the major and minor setup cost, production cost (one cardboard products) , sales data of mineral water for cup and bottle products from January 2011-April 2013 , data of production bottle mineral water for cup and bottle products from January 2011-April 2013, and the price of packaging materials . Then, data is processed to obtain the minimum inventory cost by using a phased approach and the simultaneous approach (using the software LINGO 11.0) for inventory model that considers safety stock and inventory model without considering the safety stock.Results of this research obtained an integrated inventory model between products and packaging materials that considering safety stock and without considering safety stock in PT Indomex Dwijaya Lestari. Based on the calculation, the result is valid. The proposed inventory costs are cheaper than the company's current inventory costs. The cost of the company's current inventory is Rp. 15.020.370,09 considering safety stock per month . Inventory costs in the company without considering safety stock is Rp 13.651.301,74 per month. The cost of inventory using gradual approach is Rp. 4.328.441,38 per month considering safety stock and Rp. 2.745.085,15 per month without considering safety stock. The cost of inventory using the simultaneous approach is Rp. 3.543.637,00 per month considering safety stock and Rp. 3.543.637,00 per month without considering safety stock.

Feasibility of biomass gasification is very much dependent on the cost of the gasification facility and its operation. A cost analysis model was accordingly developed to analyze the unit cost of syngas production from micro-scale biomass gasification facilities. Costs considered included all capital and operating costs. The model was applied to evaluate a scenario for Mississippi in 2008. Results of the modeling indicated that operating cost was the major part of the syngas production cost, and the single-shift operating cost could be up to 83.64% of the total annual cost of syngas production at the 60 Nm3 h-1 capacity level. Labor cost was the largest part of the operating cost and the total annual cost. The labor cost could be up to 73.60% of the total of annual operating cost and 61.56% of the total annual cost of syngas production. The unit cost and energy cost of syngas production of the 60 Nm3 h-1 facility were $0.55 Nm-3 and $0.095 MJ-1, respectively, which were higher than the $0.357 Nm-3 and $0.009 MJ-1 natural gas average retail prices in the U.S. in the fourth quarter of 2008. When the production capacity increased, the total syngas production annual cost continually increased, but the syngas unit cost markedly decreased. Therefore, the effective way to reduce costs is to plan for a higher-capacity micro-scale facility. Sensitivity analysis showed that, from the lower bound to the upper bound of the production capacity range tested (60 to 1800 Nm3 h-1), there was a shift from labor cost to equipment cost as the factor of greatest influence on syngas unit cost. Such information provided by the model identifies considerations for planning and/or operating micro-scale gasification facilities. The model can be a tool for analyzing the economics of syngas production and, in that regard, it can generate useful information for the design of smaller gasification plants.

O estudo teve como objetivo estimar o custo de produção do jumento e contextualizar com a condição socioeconômica da região semiárida brasileira. Foi proposto um modelo de estudo no qual foram considerados os custos de manutenção e produção animal, admitindo que o rebanho já existisse na propriedade com utilização das instalações disponíveis. O ciclo de produção do jumento foi estimado em 36 meses, com rebanho inicial de 100 matrizes e cinco reprodutores. Para a estimativa de produção de forragem, foram consideradas pastagens nativas da região semiárida. Foi estimado o custo de produção do jumento em US$ 258,00/ano. Entretanto, quando o jumento está integrado à unidade produtiva do segmento da agricultura familiar, esse animal deve ser considerado como ativo de produção (tração, carga e transporte). Diante da crescente demanda da pele de jumentos no mercado internacional, da ausência de políticas públicas de proteção e bem-estar desses animais, e mesmo considerando a possibilidade de integrá-los ao sistema de agricultura familiar, permanece a pergunta: quanto tempo vai levar até que os jumentos nordestinos sejam extintos? Estimar o custo unitário da produção de jumentos e considerá-los como um ativo essencial de produção na agricultura familiar pode ser um ponto de partida para diminuir seu abandono às consequências da exploração de pele.

A linear programming embedded genetic algorithm for an integrated cell formation and lot sizing considering product quality

The increasing world demand for human biologics cannot be met by current production platforms based primarily on mammalian cell culture due to prohibitive cost and limited scalability Recent progress in plant expression vector development, downstream processing, and glycoengineering has established plants as a superior alternative to biologic production Plants not only offer the traditional advantages of proper eukaryotic protein modification, potential low cost, high scalability, and increased safety but also allow the production of biologics at unprecedented speed to control potential pandemics or with specific glycoforms for better efficacy or safety (biobetters) The approval of the first plant-made biologic (PMB) by the United States Food and Drug Administration (FDA) for treating Gaucher's disease heralds a new era for PMBs and sparks new innovations in this field

An optimal solution algorithm for the constant lot-size model with equal and unequal sized batch shipments for the single product multi-stage production system

The study examined the cost and return analysis of irrigated upland tomato (Lycopersicon Esculentum) production, in Gombe State, Nigeria. Multi-stage random sampling procedure was used to select 459 respondents. Data were collected using structured questionnaire and were analysed using descriptive and inferential statistics. The result revealed that Most of the types of farms implements use for dry season tomato production in the study areas were tractors (32.4%), hand tools (37.6%) and animal traction (30.0%). Capital for dry season tomato production, the respondents in Dukku, Nafada, funakaye and Yamaltu Deba LGA respondents had a mean capital of N212,747.36, N183,662.55, N261,540.30, and N204,785.956 respectively. The findings also revealed the result of maximum likelihood estimate of parameters of the stochastic frontier production function of dry season tomato farming in the study area reveal that farm size (P< 0.001), labour (P< 0.001), farming experience (P< 0.001), and capital (P< 0.001) were the major factors statistically affecting the respondents rice production at 1%. The analysis of dry season maximum likelihood estimate of the parameter of stochastic frontier cost of tomato production showed that ploughing (P< 0.001), transplanting (P< 0.001), harvesting (P< 0.001) and capital (P< 0.001) were the determinant of cost of output of the respondents. The result further reveals the costs and return of dry season tomato farming in the study area depicts that the total variable cost of production was ₦2,384,894 with a total cost of production which is the total variable plus the fixed cost of ₦3,266,031. The revenue realized was ₦4,070,558. The net farm income for the dry season tomato farmers for one hectare in the study area was ₦804,529.23. The profit index of the respondents was ₦1.7. The major constraints to the irrigated upland tomato production were inadequate water for irrigation (23.0%), lack of irrigation facilities (20.7%), heat stress and drought (27.2%) preventing maximum productions in the study area. In addition, constraints to irrigated upland tomato farming in the study area includes high cost of irrigation services (26.0%), high-cost fertilizer (19.3%), high cost of pesticide (20.9%) and high cost of insecticide (18.2%). It was concluded that the respondents are operating at a lost and again the labour cost looking at the high cost incurred from production which clearly shows that there was over utilization of resources especially in the area of labour cost. The study made the following recommendations; efforts should be made to improve access to adequate water for irrigation purposes, there is a need to provide modern irrigation facilities to farmers to improve water management and efficiency, there is a need to promote value addition in tomato farming through processing and packaging to increase the shelf life of tomatoes and reduce post-harvest losses and farmers should be encouraged to formed cooperatives to be united in one voice to have a bargaining power over labour cost and can also make request to government on their needs and access inputs and training from policy support programme to achieve optimal yield.

This article describes a model which seeks to schedule the production of m products over the next n production planning periods in a manner which minimizes total setup, production, and inventory costs while observing all constraints imposed by the capacities of the productive resources. The model formulates this problem as a fixed charge problem, and then uses a modified version of the simplex method to locate optimal or near optimal solutions of this nonlinear programming problem. A discrete optimizing approach is used to estimate the effectiveness of the model.

The role of humans in flexible smart factories

Interest in organic dairying is increasing at a rapid pace in California, and the demand for organic milk and dairy products is growing even faster. The intent of this study was to determine the cost of organic milk production, and in particular, to determine the differences in cost of production of organic and conventional milk. Primarily we are interested in whether the differences are due to government-mandated requirements or whether they are the result of optional procedures or personal preferences. Previous studies have indicated that under organic production, the higher net returns observed on organic farming enterprises are due mainly to the lower cost of production. This conclusion is not sustained here. Our results show that the total cost of production on a per cow and a per hundredweight basis is 10–20% higher for organic producers than for conventional producers. While not strongly statistically significant, the differences appear to be due to higher feed costs, higher average labor costs, significantly higher herd replacement costs, and significant transition costs

Sales managers and factory managers may differ in their views on many points but they have at least one point in common. Both want "volume!" However, the factory manager usually looks to standardization of product, processes, and equip- ment as the basis of quantity production and low unit cost of manufacturing. The sales manager usu- ally looks to diversification in the product as the basis of volume sales. He favors changes in de- sign, style, color or finish, also novelty in the product, as necessary aids to greater volume While low price, resulting from low' production cost, is also a talking point, the sales manager sometimes brushes this aside, saying "The public will pay the price if the product is right", i.e.

Life cycle emissions and unit production cost of sustainable aviation fuel from logging residues in Georgia, United States

This paper considers a single item, imperfect economic production lot-size (EPL) model with stock-dependent demand and partial rework. In real life EPL models, defective production commences from the out-of-control state, after the passage of some time from production commencement. Its occurrence is random after the lapse of certain time and imposed here through a chance constraint. The set-up cost is partly production dependent. Unit production cost is also production dependent and a part of it is taken as environment protection cost. Defective rate is also assumed to be random and production dependent. The model is formulated as an average cost minimisation problem subject to a chance constraint and solved using a nonlinear optimisation technique - generalised reduced gradient (GRG) method through LINGO 11.0. Several special cases are derived and more specifically, the present investigation the works of Sana (2010) and Khouja and Mehrez (1994). Numerical experiments are performed to illustrate the general and particular models. Some sensitivity analyses are presented against few model parameters.

Production costs and total completion time minimization for three-stage mixed-model assembly job shop scheduling with lot streaming and batch transfer