LEAN MANUFACTURING TOOLS AND TECHNIQUES IN THE PROCESS INDUSTRY WITH A FOCUS ON STEEL

This research addresses the application of lean manufacturing concepts to the continuous production/ process sector with a focus on the steel industry. The goal of this research is to investigate how lean manufacturing tools can be adapted from the discrete to the continuous manufacturing environment, and to evaluate their benefits on a specific application instance. Although the process and discrete industry share several common characteristics, there are areas where they are very different. Both manufacturing settings have overlap, but at the extreme, each has its unique characteristics. This research attempts to identify commonalities between discrete and continuous manufacturing where lean techniques from the discrete side are directly applicable. The ideas are tested on a large steel manufacturing company (referred to as ABS). Value stream mapping is used to first map the current state and then used to identify sources of waste and to identify lean tools to try to eliminate this waste. The future state map is then developed for a system with lean tools applied to it. To quantify the benefits gained from using lean tools and techniques in the value stream mapping, a detailed simulation model is developed for ABS and a designed experiment is used to analyze the outputs of the simulation model for different lean configurations. Generalizations of the results are also provided

On electrical load tracking scheduling for a steel plant

Nolde and Morari (2010) study a steel manufacturing scheduling problem where the tasks must be scheduled such that electricity consumption matches to a pre-specified periodic energy chart. They propose a continuous time integer linear programming formulation to solve the problem. In this note, we present an alternative continuous time formulation, focused on the relative positions of tasks and time periods, that improves significantly the computation time

The „5S” strategy for continuous improvement of the manufacturing processes in autocar exhaust

The paper presents a continuous improvement strategy, process-oriented and aiming to improve manufacturing at AUTOCAR EXHAUST. The „5S” rules have immediate and significant effects on the sequence of activities in the work post, thus influencing the performance of processes in the analyzed company.quality management, continuous improvement, exhaust, AUTOCARS.

Spiral Growth Manufacturing (SGM) – A Continuous Additive Manufacturing Technology for Processing Metal Powder by Selective Laser Melting

Spiral growth manufacturing is a new innovative powder based rapid manufacturing technique. The innovation exists in the methodology in which powder layers are deposited. Unlike other pre-placed powder systems, the deposited layers move relative to the location at which they are processed. This is made possible by a rotating build drum into which powder is deposited, in spiralled layers, from a stationary hopper. With this configuration powder can be continuously deposited and levelled and simultaneously processed, eliminating delays in the build cycle. Stainless steel and cobalt-chrome powder is selectively melted using a 100W flash lamp pumped Nd:YAG laser. This paper reports on factors affecting build rate and on build strategies for creating a number of axis-symmetric thin and thick walled cylinders. Experimental results suggest that build rate for thin walled structures bonded to a substrate will ultimately be governed by tangential movements of the powder particles when frictional forces are not sufficient to accelerate the particles along a curved path, provided that enough laser power is available for melting. Even melt pool balling, which is evident when melting one layer at high speeds, diminishes in multiple layer builds due to re-melting and infilling.Mechanical Engineerin

A study into continuous improvement initiative sustainability

The idea of continuous improvement is familiar to most managers and there are many examples of how its use can increase a company’s overall performance. However, while numerous companies have adopted the approach, very few have seen the long term sustainability of such programmes. This paper reports on research that was carried out into the sustainability of continuous improvement initiatives. A case study was carried out in a manufacturing company that had been using the approach for five years. The case study identified several factors that helped to sustain the initiative but it also revealed some elements that had a negative impact

Manufacturing System Lean Improvement Design Using Discrete Event Simulation

Lean manufacturing (LM) has been used widely in the past for the continuous improvement of existing production systems. A Lean Assessment Tool (LAT) is used for assessing the overall performance of lean practices within a system, while a Discrete Event Simulation (DES) can be used for the optimization of such systems operations. Lean improvements are typically suggested after a LAT has been deployed, but validation of such improvements is rarely carried out. In the present article a methodology is presented that uses DES to model lean practices within a manufacturing system. Lean improvement scenarios are then be simulated and investigated prior to implementation, thereby enabling a systematic design of lean improvements