Industrial Engineering
Total WIP says how slow the floor is. The split says where to go and stand.
— days
From cut panel to packed garment
Little's Law needs a system in steady state, so a count taken while a large order is being launched or run out will mislead — take WIP at the same point in the week, repeatedly, before drawing conclusions. Throughput must also be measured at the exit, since counting output at sewing while WIP accumulates in finishing produces a lead time shorter than reality. The largest stage holds the most inventory but is not automatically the constraint: a stage can hold WIP because it is slow, or because the stage after it is, and only watching whether the queue grows or shrinks distinguishes the two.
Cut-to-Box Lead Time & Stage WIP Velocity Calculator — free, with the formula and a worked example, at Textile School.