Assembly Line Balancing

Assembly line balancing term used in manufacturing assembly line was first introduced by Henry Ford in the early 1900’s so the assembly line balancing concept is over a century old. It was designed to be an efficient, highly productive way of manufacturing a particular product. The basic assembly line consists of a set of workstations arranged in a linear fashion, with each station connected by a material handling device. There are various issues also in assembly line balancing or ,assembly line production, termed as assembly line balancing problems in assembly line production process that are resolved by assembly line balancing methods

Once the part enters a station, a task is then performed on the part, and the part is fed to the next operation. The time it takes to complete a task at each operation is known as the process time. The cycle time of an assembly line is predetermined by a desired production rate. This production rate is set so that the desired amount of end product is produced within a certain time period.

In order for the assembly line to maintain a certain production rate, the sum of the processing times at each station must not exceed the stations’ cycle time. If the sum of the processing times within a station is less than the cycle time, idle time is said to be present at that station.
One of the main issues concerning the development of an assembly line is how to arrange the tasks to be performed. This arrangement may be somewhat subjective, but has to be dictated by implied rules set forth by the production sequence. For the manufacturing of any item, there are some sequences of tasks that must be followed.
The assembly line balancing (ALBP) originated with the invention of the assembly line. There have been numerous methods developed to solve the different forms of the ALBP. 
Measures of final results of assembly line balancing problem

1. Line efficiency (LE) shows the percentage utilization of the line. It is expressed as ratio of total station time to the cycle time multiplied by the number of workstations.
2. Smoothness index (SI) describes relative smoothness for a given assembly line balance. Perfect balance is indicated by smoothness index 0.
3. Time of the line (LT) describes the period of time which is need for the product to be completed on an assembly line.

Conclusions
Assembly lines are a popular manufacturing structure. Assembly line balancing problem is known more than 50 years. There are hundreds exact and heuristic methods. It is very important to obtain the feasible and acceptable results. It is very important to analyze and estimate the final results and to implement the best one. Author of the chapter hopes that the presented knowledge helps to understand the problem.