The U-line Assembly Line Balancing Problem

The traditional line or straight line assembly line balancing problem considers a productionline in which stations are arranged consecutively in a line. A balance is determined by grouping tasksinto stations while moving forward through a precedence diagram. However, as a consequence ofintroducing the just-in-time (JIT) production principle it has been recognized that arranging thestations in a U-line has several advantages over the traditional configuration. In this paper the U-lineassembly line balancing problem is introduced. It is more complex than the straight line assembly linebalancing problem because tasks can be assigned by moving forward, backward, or simultaneously inboth directions through the precedence diagram. We also calculate simple problems to show that theU-line configuration frequently improves the line efficiency compared to traditional lines.