Performance Criteria in Different Assembly Line Structures

Assembly line balancing problem belongs to the most investigated topics in manufacturing systems. Since 1955 a lot of exact and heuristic methods were developed and implemented to real factories. Another problem, which occurs in balance process, is an estimation of quality measures of final results. Even optimal solution because of precedence relations includes idle times. Therefore despite of methods (exact or heuristics) a good performance criteria allow production engineers or managers to choose the most appropriate solution. The most well-known measures are: line efficiency, smoothness index and time of the line. In literature is possible to find the basic formulae. Unfortunately because of the character of given formulae, it is easy to find ambiguous conclusions about the quality of the results. The reason is a wrong interpretation of cycle time and maximum station load (time). Author presents modified formulae which allow engineers to avoid mistakes in real applications. Additionally, a relation between line structures and their measures of final balance process will be presented. In the second part of paper some numerical experiments will be discussed and the end conclusions and remarks will be given.