Sewing Line Balance Board

How to read this sheet

Station time is SMV divided by the operators on that operation, so the balancing lever is the allocation and not the method: re-engineering an operation changes its SMV and belongs upstream of this board. The bottleneck is read from the station times as staffed, which means adding an operator anywhere except the bottleneck moves the output figure not at all - the board will show it, and it is the fastest way to settle the argument. Output is reported as a rate rather than a plan: it assumes the line is fed, that there is no starvation from cutting and no blockage at packing, and that the bundle system holds enough work in process to keep every station covered. Real lines lose further output to absenteeism, machine breakdown, style change and the learning curve at the start of a run, none of which are modelled here, so treat this figure as the ceiling that balance permits rather than the output a shift will book. Operators required for a target is solved per operation and rounded up, because operators are whole people; the theoretical minimum beside it is the same arithmetic without that rounding, and it is unreachable rather than merely ambitious. An operation carrying work with nobody allocated stops the line, so the board reports zero output and counts the unstaffed operations rather than quietly reporting what the staffed stations would have made. Idle minutes are counted as paid minutes less the minutes the pieces consumed, which attributes to imbalance the whole of the difference - including any part of it a supervisor could not have removed by reallocation, since the wage bill does not distinguish.