工业工程与管理

Since the Goldratt and Cox’s (1984) seminal study, Theory of Constrains has evolved from a simple production scheduling software into a management philosophy, with practices and principles spanning a multitude of operation management disciplines. A variety of studies has investigated how production control is carried out in a Theory of Constrains environment, but most of research available lacks in providing an overall vision of this issue. In order to contribute to this gap, using theoretical investigation and the empirical study of five case studies, this article compares the characteristics of TOC with those typical of three shop floor control systems, i.e. MRP, JIT and Daily Rate. As result, the research identifies an interpretative framework based on the distinguishing characteristics of Theory of Constrains. The framework supports the analysis of the nature and scope of these four systems by highlighting the main differences between them.

In today’s global competition in manufacturing and distribution, the success of an industry is dependent on cost effective supply chain management under various markets, logistics and production uncertainties. Uncertainties in the supply chain usually decrease profit, i.e. increase total supply chain cost. Optimization is no longer a luxury but has become the order of the day. This paper specifically deals with tactical level model which considers an integrated, multi component, single product, multi stage / multi-echelon and procurement-production-distribution system design problem in a flexible supply chain network configuration. The four stages considered in this research work are vendors, manufacturing plants, warehouses and distribution centers in order of their contributions to the chain. In this work Non-Linear Inertia Weight Particle Swarm Optimization (NLIW-PSO) algorithm has been implemented to optimize of four-echelon supply chain architecture. The Total Supply Chain operating Cost (TSCC) of the supply chain network are considered as a performance indicator.

We investigate, for the first time, the structural properties of the very high voltage (400kv) power transmission network of Iran. Researches in complex systems theory have suggested that topology of the most real networks display power law shaped degree distribution, as a signature of complex networks. However, observations shed doubt on this as the degree distribution of power grids studied in different countries display exponential degree distribution rather than power law distribution (fat tailed shapes). We perform our analysis on Iran’s power grid to provide more evidence for this interesting and important result. In addition, we provide some analysis for assessing the vulnerability and reliability of the power grid.

This analysis deals with the reorganization by processes occurred in the area of research and development (R&D) in a company which is a world leader in its market, and the subsequent ergonomic changes needed. Aspects relative to organizational ergonomics are dealt with, applying to the new style of work, application of resources and the structure of task distribution. Aspects relating to cognitive and physical ergonomics are shown, focusing on environmental conditions and the interaction between the professionals of the group, and modifications made to the layout, work stations, operational procedures and training carried out. The analysis is based on a historical survey of problems encountered and their causes. Solutions adopted are based on compliance with the requirements of international rules and the needs raised by the members of the teams and professionals specialists in ergonomics. Evidences of improvement in productivity associated with the improvement of the ergonomics are presented.