The paper presents a practical example of improvement of foundry production systems in terms of post-finishing of nodular iron castings produced in the conditions of bulk production for automotive industry. The attention was paid to high labour-intensive efforts, which are difficult to be subjected to mechanization and automation. The times of actions related to grinding processing of castings in three grinding positions connected with a belt conveyor were estimated with the use of a time study method. A bottleneck as well as limiting factors were specified in a system. A number of improvements were proposed, aimed at improving work organization on the castings postfinishing line. An analysis of work ergonomics at the workplace was made in order to eliminate unnecessary and onerous for the employee actions. A model of production system using the Arena software, on which a simulation experiment was conducted, was drawn up in order to visualize the analysed phenomena. The effects of the project were shown on graphs comparing times, costs, work ergonomics and overall efficiency of production equipment indicator.
The article presents issues related to creating and realizing added value by logistic processes and processing in a casting enterprise. It discusses possibilities of improving systems of casts production by evaluating labour intensity of casts manufacture and analyzing manufacturing prime costs. Operations with added value, processes indirectly creating added value and operations without added value have been specified. The problem was presented on the example of materials flow design in a foundry, where casts are manufactured in expendable moulds and using automated foundry lines. On the basis of the Pareto analysis, a group of casts was specified whose manufacture significantly influences the functioning of the whole enterprise. Finishing treatment operations have been particularly underlined, as they are performed away from the line and are among the most labour-consuming processes during casts production.
The paper presents a practical example of improving quality and occupational safety on automated casting lines. Working conditions on the line of box moulding with horizontal mould split were analysed due to low degree of automation at the stage of cores or filters installation as well as spheroidizing mortar dosing. A simulation analysis was carried out, which was related to the grounds of introducing an automatic mortar dispenser to the mould. To carry out the research, a simulation model of a line in universal Arena software for modelling and simulation of manufacturing systems by Rockwell Software Inc. was created. A simulation experiment was carried out on a model in order to determine basic parameters of the working system. Organization and working conditions in other sections of the line were also analysed, paying particular attention to quality, ergonomics and occupational safety. Ergonomics analysis was carried out on manual cores installation workplace and filters installation workplace, and changes to these workplaces were suggested in order to eliminate actions being unnecessary and onerous for employees.
The article presents the issues of costs analysis of iron casts manufacturing using automated foundry lines. Particular attention was paid to departmental costs, conversion costs and costs of in-plant transport. After the Pareto analysis had been carried out, it was possible to set the model area of the process and focus on improving activities related to finishing of a chosen group of casts. In order to eliminate losses, the activities realised in this domain were divided into activities with added value, activities with partially added value and activities without added value. To streamline the production flow, it was proposed to change the location of workstations related to grinding, control and machining of casts. Within the process of constant improvement of manufacturing processes, the aspect of work ergonomics at a workstation was taken into account. As a result of the undertaken actions, some activities without added value were eliminated, efficiency was increased and prime costs of manufacturing casts with regard to finishing treatment were lowered.
The paper presents the issue of production processes improvement in foundries in the area of finishing treatment of iron casts manufactured on automated foundry lines with vertical or horizontal mould division. Due to numerous factors which influence the efficiency of the processes, multi-criterion assessment tools were proposed in order to select the optimal solution for the assumed criteria. After determining the criteria weight using the Saaty method, a simulation experiment was designed and carried out which presents possible scenarios of casts finishing treatment operations. Basing on experiment reports from a computer model, particular solutions were evaluated using the Yager’s method. The evaluation of the experiment results was performed by experts who assessed different options according to each of the criteria adopted. After the establishment of the total standardized ratings by averaging the scores given by individual experts, the final decision was generated. Using the presented method, the best solution was chosen from among the analyzed scenarios.
The scope of this work focuses on the aspects of quality and safety assurance of the iron cast manufacturing processes. Special attention was given to the processes of quality control and after-machining of iron casts manufactured on automatic foundry lines. Due to low level of automation and huge work intensity at this stage of the process, a model area was established which underwent reorganization in accordance with the assumptions of the World Class Manufacturing (WCM). An analysis of work intensity was carried out and the costs were divided in order to identify operations with no value added, particularly at individual manufacturing departments. Also an analysis of ergonomics at work stations was carried out to eliminate activities that are uncomfortable and dangerous to the workers' health. Several solutions were proposed in terms of rationalization of work organization at iron cast after-machining work stations. The proposed solutions were assessed with the use of multi-criteria assessment tools and then the best variant was selected based on the assumed optimization criteria. The summary of the obtained results reflects benefits from implementation of the proposed solutions.