Layout Models for the Food Processing Industry
2. Related Research
A plant layout is designed to obtain a physical arrangement of different entities of a facility that most economically meets the required output, in terms of both quantity and quality. According to C. S. Tak and L. Yadav, a plant layout ideally involves allocation of space and arrangement of equipment in such a manner that overall operating costs are minimised. Three main types of layouts, product layout, process layout, and group layout, are commonly encountered in manufacturing systems. Group layouts can further be categorised into flow line, cell, and centre. These are shown in Figure 1, and, according to A. K. Jain, V. Khare, and P. Mishra, the distinction between these types of layouts is made based on system characteristics such as production volume and product variety. It is reported that a well-designed manufacturing layout can reduce the operating cost by 50%.
Figure 1 Layout types.
2.1. Layout Efficiency
In order to assess the efficiency of a layout, key performance indicators (KPIs) are used. The commonly used KPIs are travelling distance (m), distance travelled times weight (mkg), goods movement, personnel movement, overall equipment efficiency (OEE), energy efficiency, and waste generation. However, KPIs suitable for the food manufacturing need to be identified and incorporated into the assessment criteria of layout efficiency in order to address the food safety considerations. This also enables effective determination of the efficiency improvement of the food manufacturing processes when layout modifications are performed.
2.2. Food Processing Technology
The primary concern of food manufacturers is to produce something that is wholesome and safe, that is, free from pathogenic microorganisms and chemical and foreign body contamination. Food items are perishable and become unsuitable for consumption with time. Although it cannot be prevented, one aim of food processing is to slow down the rate of deterioration by selecting appropriate methods of processing, ingredient formulations, packaging, and storage conditions. In order to make food items safe for consumption, food processing plants take measures to eliminate the possibility of microbial, chemical, and physical contamination. Thus, it becomes a key factor of concern, and layout design should essentially help to prevent direct and cross contamination of the products being manufactured. Hence, the layouts of the food processing factories have to be designed to meet food safety requirements on top of production efficiency. This is the main envisaged difference between the layouts of food processing and other manufacturing plants. Thus it can be concluded that the food processing plants add a new dimension to the common layout design problem.
2.3. Quality Standards Applicable for the Food Processing Industry
Many guidelines are available to regulate the food manufacturing processes. In the food processing sector, Quality Assurance (QA) systems are used to improve quality and reduce costs whilst HACCP programs are specifically deployed to assure food safety. Based on management principles, HACCP and GMP have been implemented to help plants to maintain high levels of hygiene. HACCP systems establish process control by identifying points in the production process that are most critical to monitor and control in terms of contamination. It is widely recognised in the food industry as an effective approach to establish good production, sanitation, and manufacturing practices that produce food items that are safe to consume [14]. Therefore, it can be concluded that QA and HACCP implemented in concert facilitate improvements in both production efficiency and product safety.
Considering the above factors, an area that needs attention in the food processing industry is the relationship between hygiene and the layout of the processing plants. Aspects of food hygiene have been addressed in different disciplines and a considerable amount of knowledge is available. However, this knowledge is not systematically linked to the evaluation and design of layouts for food processing. The literature on layout planning has thus far inadequately addressed the influence of hygiene factors on the specific nature of the food processing companies.