This master thesis has been written during the autumn of 2007 and in the month of
January 2008. It investigates how the Lean philosophy can be used in Warehousing
businesses. Further it gives example of tools that can help Warehousing companies to
become Leaner in their business.
There is a contradiction between Lean Thinking and Warehousing practice today,
since Lean strive at being just in time with a pull flow with no batching production
and with preferably no inventory kept between the different processes. This is an
ideal scenario. In real life there exist variation in demand, uncertainty in lead time and
long lead times that cannot be fully predicted. This makes a warehouse necessary to
provide items to the production, assembling or customer in time.
The warehouses doesn’t add any extra value to the items themselves but only to
customers by giving it in the time that the customer wants it, in the right amount and
in the right quality. This makes the processes in the warehouse that is necessary for
maintaining that ability; necessary non-value added processes. The other processes
that aren’t necessary are just non-value added processes. The warehouse can also be
preferred for distribution purposes. But since nothing the warehouse do with the item
gives it more value in monetary terminology, little handling of the item as possible is
to be preferred. But as mentioned before there are necessary non value added
processes and there are those who are just non value added. The goal is to avoid the
non value added activities and improve the necessary non-value added processes if
they can’t be avoided as well.
One way to improve the necessary value added process picking is to place the items
in a matter that reduce the work for the picker when picking. It could be placing them
in appropriate heights and on picking frequency to reduce travel time. This could be
done by an ABC-classification on the picking frequency and dividing the picking area
into zones depending on the ABC.
Another way to improve the picking process is to visualize and assign the workload
as optimal as possible. This could be done with the Heijunka concept together with
the shipping order logic.