Warehouse

My vision of a warehouse and the processes running there I try to base on ideas of Lean philosophy. Though all publications about Lean concern basically an area of industrial activity of the companies, but in my opinion the given approach as is remarkable exactly for warehouse technologies.

The basic idea lies in the following: if any action, operation or process does not add value to a product from the point of view of the client, this action, operation or process is considered as a loss, that is bringing losses to the company. Classically all loss is divided into seven classes.

   1. The processes leading to overproduction.
   2. The processes leading to stocks overflow.
   3. The processes creating defects.
   4. The processes maintaining superfluous actions.
   5. Processes of excessive handling.
   6. Expectation processes.
   7. Processes of superfluous transportation.

I will try to consider some of this loss classes with reference to warehouse technologies.

1. Overproduction.
In a warehouse case it means e.g. arrival of products more than a warehouse can hold. Other case  is ordering ten vehicles for loading though simultaneously only five vehicles can stand. The others stand in a queue, stand idle, substitute. But the most widespread case is when there are 100 waybills given for assemblage and the goods on 70 of them will be collected this afternoon, and others 30 will be dispatched at night or tomorrow morning. The warehouse starts to collect simultaneously all waybills successively. First, collected, but not dispatched waybills need to be stored somewhere, thereby increasing the area of a zone of dispatch. Secondly, the number of workers that need to be turned in  increases so they can work simultaneously at an o'clock to reduce queues (but after the end of the hour-peak half people will be idle). Thirdly, there comes the client right now and has to wait in turn, because a part of people is busy on assembling tomorrow's waybills.

2. Overflow of stocks.
This kind of loss, maybe is not absolutely correct to consider from the point of view of warehouse technologies as the warehouse just is intended for materials handling and a custody of stocks. There will be no stocks, there will be no warehouse. But looking more widely becomes clear, that any stock are the circulating assets, laying dead consignment. At any enterprise the lion's share of expenses to have on maintenance of stocks (flowing, insurance, seasonal), and inventory balance reduction should be a priority for enterprise management. But as supplying the enterprise is not usually something the management of a warehouse or department of warehouse logistics do, I won't give details on optimisation methods of stocks, though I have sufficient knowledge in this area. Though in a warehouse also there can be overstockages - people (when the part of people idles because of imperfection of the organisation processes), the warehouse engineering and the equipment etc.

3. Defects, errors, waste.

The obvious loss causing lack of material and human resources. At depot it first of all happens because of a wrong complete set, wrong good accpetance because of quality (waste), errors in placing goods on storage, wrong storage … Though the stroke-coding and address system of storage allow to lower sharply number of errors at assemblage, and the accurate regulation of actions can reduce other errors.

4. Superfluous operations and movings on a workplace.
If the worker attends to search of the necessary document or follows a cart or the empty pallet for some metres from his work place, it also does not add value to a product from the point of view of the client. Due to the statistics 50 % of time the collector spends for moving on a warehouse durint order batching. The main rule of placing goods at depot: the goods are put there where it is more convenient to take them. But  it is more often that everything goes on the contrary - the goods are put there where it is more convenient to put them. As a result the situation when the demand item appears in the most distant corner, and the type-setter twenty times a day is running some extra meters to get it while the unmarketable goods are the closest to an exit. And after all there is elementary ABC-XYZ analysis which allows to avoid such situations. Very often the type-setter runs on a warehouse in search of the necessary goods and cannot find it, and spends a lot of time on it. Usually it is thought, that the type-setter is guilty because he cannot keep in memory places of all 3-5 thousand names or simply did not see, where that have been put upon arrival. Though actually the manager is guilty, who considers that the address system of storage is not necessary for the warehouse.