Replenishment – Make-To-Stock Sawmilling

Replenishment – Make-To-Stock Sawmilling

A large private sawmilling and timber treatment
operation in the lower North Island with 75 employees, $13M turnover,
producing 36,000 cubic meters of timber.

milling shares with other primary production the fact that there are
“co-products,” that is, in milling a tree all the products from
the break-down of the log must be sold or disposed of.

each log type there is some latitude or discretion as to the type and
volume of sawn product to be produced. We installed a simple
replenishment system at this plant. Replenishment is fundamentally
different from the minimum/maximum stock systems used in most
industries. It is much closer to stocking a supermarket shelf, what
is sold today is replenished the next, trying to keep a steady flow
of work-in-process in the system and appropriate stock “buffers;”
not too empty and not too full. However, in timber production the
process time for the same source timber might vary from days to many
weeks depending upon whether the timber is treated, the particular
treatment used, and final finishing required.

buffers are shown in red, yellow, and green diagrams above. The
presence of green means the buffers have sufficient stock, the
presence of red means the buffers have insufficient stock. Subtle,
day-to-day alterations in the cutting schedule can accommodate moves
in the market demand without the previous reactionary stance of
making too much and making too little.

This is a project made by Dr. Kelvyn himself

Dr Kelvyn