Balancing the planned and actual production time within a steelwork fabrication company

Abstract

In order to be sustainable in an ever growing competitive market, optimisation is required in a company to remain reliable and respond to change. The steel fabricator, Louwill Engineering, is faced with an imbalance in planned and actual production times in their workshop which leads to late delivery of items to succeeding companies in the inter-company supply chain and furthermore to overall late delivery of orders to site. Ine cient material ow in the fabrication facility, high levels of work-in-process inventory and non- aligned prioritization of jobs are identi ed as the major causes of this problem. This project focusses on eliminating wasteful time in the fabrication process and improving the material ow within the fabrication process with the aim of achieving a balanced state in the production time of items. Literature research was done to identify the most appropriate techniques and methodologies to use in solving the above-mentioned causes of the imbalance production time problem. The research reviews di erent simulation techniques, facility layout alternatives and development algorithms and facility alter- native selection methods. A simulation optimisation methodology is developed as a solution to address the imbalance production time problem. The methodology consists of the integration of simulation modelling and facility layout design. The fabrication process of Louwill is modelled as a Discrete Event Simulation and di erent facility layout alternatives are developed by means of the systematic layout planning procedure and alternative improvement opportunities. The Preference Selection Index method is used to identify the best facility alternative among those tested for the fabrication workshop. The selected best facility alternative along with two other alternatives are analysed by means of a com- parative study. This study analyses the a ect of a pure layout, a pure process and a combinational layout and process improvement have on the selection attributes. These selection attributes are the time an item spends in production, re-processes and storage areas and the time of moving an item between functional departments. Based on the results of the Preference Selection Index (PSI) methodology and the comparative study it is recommended that the company changes the current facility layout to the recommended product layout. The recommended product layout consists of a U-shaped production line with the functional departments placed in the order of the xed process sequence, recommended for the workshop. It is also recommended that the company implement the supplementary improvements opportunities and adopts the xed process sequence suggested. These improvements will result in a reduction of the actual time an item spends in the fabrication workshop as it improves the material ow in the workshop, resulting in more balanced planned and actual production times of items. The company itself, the succeeding intermediate companies in the inter-company supply chain, and the end customer will bene t from balancing the planned and actual production times of items. This balance will result in enhanced supply chain relationships, improved fabrication process performance, customer satisfaction, delivering of items in the promised lead time to the next intermediate company and overall on-time delivery to the end customer.