Line balancing is the process of assigning tasks to workstations, so that workstations have approximately equal time requirements.
We use line balancing to
- minimize idle time
- balance bottlenecks
A constraint slows the process down and results in waiting for downstream operations.
Excess capacity results in waiting and no absorption of fixed costs.
Everyone is doing the same amount of work. Doing the same amount of work to customer requirement. Variation is ‘smoothed’. No one overburdened. No one waiting.
Everyone working together in a BALANCED fashion.
In product layouts, when we want to improve productivity, we need to find and improve critical operations, known as bottlenecks.
Productivity improvements to any non-bottleneck operation will NOT improve productivity of the system.
Heuristics for working out Line Balancing Problem:
- SPT - Shortest Processing Time
- Longest Path in Network
Cycle time – the maximum time allowed at each workstation before the work moves on. Cycle time determines the rate of output.
Line Balancing Formulas:
Minimum Cycle Time = longest single task time
Maximum Cycle Time = sum of all task times
Nmin = theoretical minimum number of stations
OT = operating time/day
CT = cycle time
D = desired output rate
Nmin = 3t/CT CT = OT/D Output capacity = OT/CT