Accumulation systems help to maximize production line efficiencies.  Most all production lines have bottlenecks and it is the bottleneck that requires the attention of how to plan for accumulation.  If other machine downtime causes the bottleneck to shut down, the production line will benefit from accumulation.  Should any downstream machine be capable of a higher production rates than the previous machine in the line, accumulation should be considered.

When evaluating accumulation requirements, the accumulation size should be equal to or somewhat greater than the machine with the longest mean time to repair (MTTR).  If you do not plan enough accumulation, the production line efficiency will be affected which requires everything to run longer to make daily production goals.  Addressing the accumulation requirements for your specific production line needs should be done in the planning stage, too often accumulation becomes a point of conversation after a production line installation.  With all accumulation systems, space claim is a requirement not matter what the style of accumulation.