International Journal of Research in Industrial Engineering
Volume:8 Issue: 1, spring 2019

In recent years, robots have been an eminent solution for manufacturers to facilitate their process and focus on a variety of their products. As the importance of robot usages, our paper focuses on the robotics assembly line. In this paper, we have considered the cycle time, robot operational costs, robot purchase costs, and robot energy consumptions. In the following, we add robot failure rates to have an efficient and high-quality assembly line. The presented model is a multi-objective problem, therefore, the linear programming methods as goal programming and augmented ε-constraint method are applied to optimize the problem. In the end, we have considered a case study to examine and show the applicability of the proposed model on the real situation.

In this paper, a two-person zero-sum matrix game with fuzzy numbers payoff is introduced. Using the fuzzy number comparison introduced by Rouben's method (1991), the fuzzy payoff is converted into the corresponding deterministic payoff. Then, for each player, a linear programming problem is formulated. Also, a solution procedure for solving each problem is proposed. Finally, a numerical example is given for illustration.

The purpose of this study is to provide a proper method for evaluating performance of teachers, which leads to authorities awareness about the quality and quantity of activities that are acceptable to the organization; also creating the grounds for empowering human resources, reduction of dissatisfaction, and complaints. This can result in eliminating discrimination or unfair judgments and therefore reduction of tensions, and conflicts between managers and employees. The Analytic Hierarchy Process (AHP) which was developed by Saaty is a decision analysis tool. It has been applied to many different decision fields. In this paper, we use AHP as a performance assessment tool to inquire diverse assessments in the organization about the performance of each employee. Since the number of the items to be compared in AHP is increased, the number of pairwise comparisons that each assessor answer, are increased drastically. So, we develop a method called EVMP to elicit the preference vector of pairwise comparison matrices with missing entries. The newly developed method is tested in a school; the generated results have been proved by experts.

Packaging plays an important role in ensuring that the produced product is well contained, protected, and preserved. Due to its significance, the researcher decided to undertake research aiming at examining the awareness of local producers towards products’ packaging. This research employs a descriptive design in carrying it out where a sample of 120 respondents from different companies give a list of questions regarding packaging and also inspection is done in the market to observe how the products have been packed. Findings revealed that the awareness of Tanzanian local producers is still very low whereby 75% of packaging workers are unskilled. Also, training regarding packaging is not conducted in an effective manner as most companies train their employee only once when they employ them. It is also noted that the local producers mainly focus on the ability of the package to contain the product paying less attention to the ability of the package to protect and preserve. Based on these findings, it is suggested that the knowledge of value chain management has to be imparted to local producers by the local business institution. It is also proposed that training should be given frequently to packaging crew to ensure they do their job effectively. Moreover, it is recommended that to increase the efficiency and cost reduction, it is better for companies to employ experienced workers or those with at least form six or high level of education in packaging section as it is easy to train and they can understand easily.

In today’s competitive business environment, supply chain performance is one of the most critical issues in the various industries; there is much argumentation about the fact that supply chain performance is the basis of the supply chain management efficiency. In this regard, the distribution sector is the most important part of the supply chain. Due to the pulse of a company is in the hands of its sales and distribution department. This article proposes a new mixed integrated linear programming model MILP for scheduling distribution channel membership based on capillary marketing by considering staffs experiences at Pak's pasteurized dairy in one month. The purpose of this study is to reduce the costs of the company along with the increase in sales. Constraints affecting target functions such as minimum sales per employee and maximum overtime days are also considered. The computational experiment by GAMS software demonstrates the effectiveness of the model in reaching its objectives.

Crude oil is a predominant natural resource and also it causes the metallic corrosion in the industry of crude oil refining due to some corrosive properties of crude oils. In the current research, it is expected to investigate the effect of such compounds of crude oils on the rate of corrosion of seven different types of ferrous metals which are frequently used in the crude oil refining industries. The sulfur content, salt content, acidity, and mercaptans content of each crude oil are determined in order to use XRF analyzer, salt analyzer, and titration methods. A set of equal size metal pieces are immersed in both crude oils separately for 15, 30, and 45 days and their corrosion rates are determined by using relative weight loss after these time periods while observing the corroded metal surface under the optical microscope, and the dissolved metal concentration in each crude oil sample is tested by the AAS. The hardness of each metal piece is tested before and after the immersion in crude oil with the aid of Vicker’s hardness tester. It is found that a higher amount of sulfur, acidity, and mercaptans and lower amount of salt present in Das blend than Murban. We have found there is some significant rate of corrosion from most of the metals and higher amount of dissolved metallic concentration in samples of both crude oils with respect to those metals. It is observed that there is a slight reduction in hardness of all metal pieces due to the corrosion.

This paper deals with the number theoretic properties of non-unit elements of the ring Zn. Let D be the set of all non-trivial divisors of a positive integer n. Let D1 and D2 be the subsets of D having the least common multiple which are incongruent to zero modulo n with every other element of D and congruent to zero modulo n with at least one another element of D, respectively. Then D can be written as the disjoint union of D1 and D2 in Zn. We explore the results on these sets based on all the characterizations of n. We obtain a formula for enumerating the cardinality of the set of all non-unit elements in Zn whose principal ideals are equal. Further, we present an algorithm for enumerating these sets of all non-unit elements.