Production economics

This study examines the effect of inventory management on organizational operations, productivity, as a means of causing the profitability of companies. The study was, therefore designed to study how the manufacturing firms managed their inventory materials. We used questionnaire in collecting our data. The data collected was analysed using spearman's rank-order correlation coefficient and the Pearson product-moment correlation coefficient. The findings indicated that the method used by 7Up Bottling Company to manage their inventories in both raw materials and the finished product was efficient as the amount of naira saved in the course of purchase have more effect on the profitability of the company during production/ selling of the finished goods. Controlled purchasing is found to be cost-effective. The study recommends the following: an adoption and application of the economic order quantity (EOQ) model to save cost and make the operations more efficient.

Currently the industry is trying to improve its competitiveness. This makes the manufacturingindustry needs to adapt the Lean-Kaizen concept. Lean-Kaizen means eliminating waste through small improvements made on an ongoing basis. This research takes a case study at PT Inoac Poltechno Indonesia, which is engaged in foam production. The current production target is only 56% of the planned target. Besides that, there are found many defective products and activities that have no added value. Furthermore, a map of the current condition is made to find waste and know the kaizen that will be carried out. Furthermore, a future map was developed with work standardization and Value Stream Mapping to determine activities that have no added value. Calculation of Waste Assessment Model (WAM), shows the biggest waste is defect (26.73%), inventory (15.79%), and waiting (13.35%). This study found that by adding trolley, adding operators, making SOPs, scheduling engine maintenance would make non-va...

The study which was conducted in Bayelsa State, Nigeria, examined the socioeconomic characteristics of catfish (Clarias gariepinus) production in Bayelsa State, Nigeria. A multi-stage sampling technique was used to select three (3) Local Government Areas (Yenagoa, Ogbia and Kolokuma-Opokuma) purposively based on their predominance in commercial catfish farming and randomly five (5) communities each from the three (3) LGAs. Furthermore eight (8) catfish farmers in each community were randomly selected making a total number of one hundred and twenty (120) catfish farmers and analyzed using descriptive statistics and budgetary technique. The costs and returns analysis indicated that the Total Fixed Cost was ₦881,500.00 while Total Variable Cost was ₦3,956,025.01 with Net Farm Income of ₦3,113,183.32 during production period of six months. Return on investment was ₦0.64 which implies profitability of catfish production in the study area. The study also identified high cost of feed (18.6%), inadequate finance (13.2%), inadequate seed supply (11.1%), lack of land (10.5%), lack of organized market (9.5%), high cost of transportation (8.9%), lack of modern technologies (7.4%), high cost of labour (7.4%), inadequate water supply (6.3%), high spread of pest and disease (5.3%) and inadequate storage facilities (3.3%) were the major problems faced by catfish farmers. It is therefore suggested that there is a need of government support in terms of revitalization and prioritizing funding of extension delivery system of the state owned Agricultural Development Programmes (ADPs). This will help to mobilize and motivate the extension agents to reach the target farmers with relevant information on improved farm management practices.

In today's business transactions, there are various reasons, namely, bulk purchase discounts, re-ordering costs, seasonality of products, inflation induced demand, etc., which force the buyer to order more than the warehouse capacity. Such situations call for additional storage space to store the excess units purchased. This additional storage space is typically a rented warehouse. Inflation plays a very interesting and significant role here: It increases the cost of goods. To safeguard from the rising prices, during the inflation regime, the organisation prefers to keep a higher inventory, thereby increasing the aggregate demand. This additional inventory needs additional storage space, which is facilitated by a rented warehouse. Ignoring the effects of the time value of money and inflation might yield misleading results. In this study, a two-warehouse inventory model with linear trend in demand under inflationary conditions having different rates of deterioration has been developed. Shortages at the owned warehouse are also allowed subject to partial backlogging. The solution methodology provided in the model helps to decide on the feasibility of renting a warehouse. Finally, findings have been illustrated with the help of numerical examples. Comprehensive sensitivity analysis has also been provided.

The aim of the paper is to investigate the well-known bullwhip effect of supply chains. Control theoretic analysis of bullwhip effect is extensively analyzed in the literature with the Laplace transform. This paper tries to examine the effect for an extended Holt–Modigliani–Muth–Simon model. A two-stage supply chain (supplier–manufacturer) is studied with quadratic costs functional. It is assumed that both firms minimize the relevant costs. The order of the manufacturer is delayed with a known constant. Two cases are examined: supplier and manufacturer minimize the relevant costs decentralized, and a centralized decision rule. The question is answered, how to decrease the bullwhip effect.

There is a unidirectional relationship existing between agricultural productivity, climate change as well as food security in developed and developing economies of the world. Developing countries like Nigeria often depend on rainwater for the production of yam, among other crops. However, unpredictable changes in the onset of rains in the last 10 years have led to situations where yam planted with the arrival of early rains get smothered in the soil by an unexpected dry spell; resulting in harvest failures in Nigeria and other ecosystems that rely on rain-fed agriculture. Specifically, the study determined the effect of the socioeconomic characteristics on yam production in Cross River S, Nigeria; and further identified the activities of the farmers that exacerbate the effect of climate change in the study area. The study employed a survey design. A multi-stage sampling technique was adopted to select 150 respondents for the study. The yam output was proxied by farmers' income and was regressed against the independent variables. Ordinary Least Square analysis, Likert rating scale and descriptive statistics were employed to achieve the objectives. The results show that the socioeconomic effect on yam production is statistically significant at P of 0.05. The prevalent farm practices in the area according to the order of intensity were; burning of firewood-16%, burning of crop residues and household waste as well as burning of fossil fuel by automobile-11%, deforestation and the use of fertilizer-10%, bush burning, use of herbicide/insecticide and burning of fossil fuel by industries-9%, continuous cropping-8% and use of insecticide/pesticide-7%. It was recommended that policies should be put in place to regulate anthropogenic practices that foster climate change and variability. The government is advised to deploy more extension agents who are knowledgeable on

This study was carried out to indicate the factors, which could determine the burden of disease among rice farming households in Ogun state in Nigeria. Multi-stage sampling procedure was used to select 240 rice farming households. The study showed that nearly all households took drugs or medicines without consulting a doctor or pharmacist. Low level of income (85.33%), lack of awareness of health facilities (52.02%), low level of education (58.22%), as well as hindrances in distance and difficult terrains towards health facilities (75.11%) were indicated as the critical problems being faced by the households from using public health facilities. Sex, household size, off-farm income, distance to health care services and dirt floor of home were positively and significantly considered to influence disease burden, while age, cooperative membership, labor used and health conditions had negative effects. The study concluded that increased distance to health care services increased the burden of diseases of the households. It was therefore, recommended that health facilities should be located nearer to the people's locations to increase its appropriate use. This would gradually improve their health conditions, and thereby reduce the ill-health cost in the long run. Contribution/ Originality This study examined factors influencing economic burden of diseases among rice farming households. This study will further serve as a guide to government, non-governmental organizations and other stakeholders involved in provision of health care facilities, it will also be a prima facie in adding to the sparse knowledge that exist in the area of factors influencing farmers ill-health cost.

When computing production plans and available-to-promise statements, the randomness of flow times and yield rates are the two major sources of uncertainty. Considering both of these uncertainties, this study employs a simple formula for computing the standard deviation for cumulative good product output of a particular product type at a particular time. Using this standard deviation, the necessary safety stock for that product type at that time can be obtained. This study was motivated by semiconductor wafer manufacturing, which requires many process steps performed by highly unreliable equipment. Such an environment causes the means and the variances in flow times to be generally larger than those for other industries. It also makes yield rates uncertain. Thus, when making order quotations and calculating production plans, safety stocks must be used to guard against the uncertainties of the manufacturing processes to ensure on-time-delivery ratios and to provide better customer service.

In stochastic inventory systems unfolding uncertainties in demand lead to the revision of earlier replenishment plans which in turn results in an instability or so-called system nervousness. In this paper, we provide the grounds for measuring system nervousness in non-stationary demand environments, and gauge the stability and the cost performances of (R,S) and (s,S) inventory policies. Our results reveal that, both the stability and the cost performance of inventory policies are affected by the demand pattern as well as the cost parameters, and the (R,S) policy has the potential to replace the cost-optimal (s,S) policy for systems with limited flexibility.