Manufacturing Lead Time (MLT)

Manufacturing lead-time is the total time needed to process a given part or product through the plant. MLT of the component/product is mathematically shown as  below:

Equation 1

 where T_suji = Setup time for ith operation of jth component/product,

              Q_j = Quantity of product in the batch being processed,

              T_cji = Operation cycle time for operation i, and                                

             T_noji = non-operational time associated with operation i.

The non-operation times involve temporary storage, handling, inspection and other causes of delay.

The above equation of MLT might be further simplified by supposing that all setup, non-operational and operational times are equal for all the machines (n₀) processing the batch of products.

Equation 2

∴          MLT = n₀ (T_su + QT_c + T_n0)

Equation 3

 MLT for a job shop industry (Q = 1), MLT = n₀ (T_su + T_c + T_n0)

MLT for a flow line mass production industry:

Equation 4

MLT = n₀ T_c (neglecting transportation times)