Zoning of a warehouse

Rule No. 1. Increasing storage density, do not sacrifice the speed of execution of operations

Organizing at itself racks, including stuffed, calculate time which will be spent by the employee on extraction of a load, in particular from an upper tier of the most distant pallets. Can happen so that the employee will need one of such a pallet. As a result it will spend a lot of time that to get it.

For example, in one of warehouses of large manufacturing enterprise, the management made the decision to set stuffed racks for increase in density of storage. Density really increased, but transactions began to be executed much more slowly. For extraction of the most distant pallet from an upper tier it was possible to spend about half an hour. Such examples really exist in practice. Now at this enterprise consider the possibility of acquisition of shuttles. But as construction was not adapted for them initially, it will entail additional costs on acquisition and installation of required component parts and also on release and refill of racks. In this regard, if the number of transactions increases, analyze a possibility of acquisition of the equipment and its further "upgrade".

Also at design of a warehouse with gravitational racks it is necessary to pay attention to length of canals and the front of selection if it is about boxed gravitation. Quite often in warehouses there is a situation when boxed gravitation costs thin because of unfairly high-capacity channels. At the same time, for placement of all necessary SKU there is not enough place because of the insufficient front of selection.

For an example, imagine the large meat processing plant which ordered the project of the distribution center for direct shipment to shops. The project was implemented by forces of equipment supplier who set the channel length of boxed gravitation in 18 plastic boxes. The superficial analysis showed that 18 boxes are a one-time batch of storage of loads of category "A" on the outgoing tonnage. At the same time, the C group including about 50% of number of active SKU is filled less, than for 50%. Because of it a half of channels stand idle in a thin status.

Rule No. 2. Consider capacity of avenues and corridors that employees and the equipment could miss each other

Density of storage can be increased not only by means of specialized racks, but also by means of simple reduction of width of passes and also due to reduction of the operational areas of a warehouse. It would be desirable to put separate emphasis and on need of the choice of chatter-free width, proceeding not only from among places which we want to receive, but also based on intensity of transactions.

Example: in one of warehouses it was necessary to dismantle a part of shelf construction of the mezzanine to receive broad central pass that led to performance improvement more, than for 30%. The reason of such growth is simple - people began "face" much less in passes.

Similar to an example, the chatter-free width needs to be taken into account during the work with stuffed racks or the mixed stack. Trying to get the necessary pallets, employees can be a lot of time in passes, than can prevent the colleagues. Therefore it is desirable to create the cyclogram for each operational section and to define chatter-free width taking into account auxiliary transactions.

Often the problem of excessive load of avenues is tried to be transferred to WMS - a system, indicating an opportunity to evenly distribute resources on the area of a warehouse. Separately it should be noted if we place goods of category "A" on access rate on one small section, then the only way that WMS - a system provided us a uniform load - it is separation of transactions in time. It means that so far some employees execute transactions, others wait for them. The uniform load is a package of measures which begin with the analysis of goods flows on an input and an exit, and developments of an algorithm of placement. If we cannot optimum place, we will not be able optimum to complete orders.

Let's give an example, than it is fraught. In a pharmaceutical warehouse decided to increase storage density, implemented narrow-passage technology and started a set of orders in avenues. Now imagine how it looks. In the narrow avenue the employee with the hydraulic cart with a pallet moves, executing different transactions in the constrained conditions. His colleagues coming into the same narrow avenue follow it queue and their performance depends on that, how long going ahead will execute the transaction.

Of course, when using narrow-passage technology there are not only grim stories. One of such - when in narrow-passage technology warehouses specialized high-rise pickers by means of whom it is possible to select loads from any tier use. However, such solution can have "reefs" too.

For example, if we want to move from a row in a row at a complete set of orders, we should assign each picker to the zone of a warehouse. If we want to increase overall performance, then it is reached by increase in number of items of equipment and reduction of an area of responsibility of each such unit. As a result, we can receive a high-intensity warehouse where in each pass there will be the item of equipment. Such approach will cost much, plus to everything will appear need to solve a problem of the fragmented set of orders - when each item of equipment collects only that part which has relations to its area of responsibility.

Rule No. 3. Segment the storage area not only on "AVS", but also being guided by the principle of minimization of labor costs at execution of operations

Structuring the storage area - a task rather creative. To define what algorithm of loads will be optimal, is required to carry out modeling, to define characteristics of SKU and to count resources consumptions on the accompanying transactions. Despite it, simple ABC analysis on access rate that the goods relating to the A group were placed closer to a zone of export or consolidation where already ready orders gather quite often becomes.

If to provide that products have additional characteristics, for example - heavy, easy, brittle - it already means need of development of a route of a bypass of cells at set under orders if structure such is that goods with different characteristics are gathered by one employee. Now let's think: what will be effect of ABC analysis if is the closest to a zone of export there is a fragile load which is required to us in the last queue, and further everything - a load heavy which we should take first of all?

For an example we will take a warehouse of low alcohol drinks and the accompanying products. Not only that at a set of such goods it is necessary to observe a certain sequence for different packaging (glass, tin, PET, etc.), it is necessary to consider also other nuances. For example, the fragile accompanying loads need to be stacked on top on heavy beer, and not vice versa. For this reason one ABC analysis on access rate in such warehouse will give nothing. Complex approach will be required.

If we placed goods according to a necessary priority of set, then placement of the arriving loads in cells to minimize labor costs on replenishment transaction will be the next stage. Thus we try to reduce labor costs within end-to-end process of cargo handling, but we do not optimize specific transactions to the detriment of cumulative effect.

Rule No. 4. Do not mix the loads having different points of appointment which processing means use of the different equipment on one operational square

If in a warehouse sections for transfer of loads between different process areas (so-called "transit" sections) are organized, then it is necessary to draw the closest attention to structure of these sections.

The matter is that one section can serve for transfer of loads to the different items of equipment having different opportunities. Thus, the operator of the equipment who drove up to such section for task performance should not only (in the presence of WMS) to receive it in electronic form, but also to have an opportunity to find a required object (a pallet, a box, etc.) physically. For this purpose sections need to be organized with a possibility of an entrance to each object which is in its framework, or to divide into several cells, within each of which there will be only loads meaning further processing by means of the specific equipment.

Example: employees on one tier gather products and take out to one big cell under the name "Set Transit". Further products should get on different levels of a warehouse: the first (to docks) and the second (the mezzanine, on marking). The employees performing movement tasks to docks and on the mezzanine use the different equipment. The problem is that at the organization of transit section, it was not separated into separate cells and did not provide a possibility of processing of loads of each separate group.

Now provide that in this one cell is very densely cost in a large number by pallets. A system directs the employee with the hydraulic cart to a specific pallet, but it is forced by other loads. The employee passes into the mode of receiving a task on scanning of any pallet, scans a barcode of the next pallet, but the WMS system answers: "this task is out of your area of responsibility" as this pallet is planned for marking - on the mezzanine. Thus we received costs of extra time because to go around pallets and to scan a barcode of each of them, hoping that it will have an admissible point of appointment, it is possible very long.

Irrespective of existence or absence in a management system warehouse, provide due ergonomics of execution of operations. If within one transit section to organize two physical areas where within one products going on the same level, and on other square – products for other level will be placed, then employees even in the absence of the automation equipment will accurately understand that their tasks are concentrated within specific section of a warehouse.

Do not neglect a marking. On productions, as a rule, it is need as very high intensity of transactions where both pipelines, and a certain zoning can be used is inherent to them. Probability of assumption of an error should be the smallest. As for a warehouse, the situation with intensity of transactions can be at all not less, and sometimes it is even more, than on production. Therefore the marking needs to be organized so that it was clear to employees what they work with as they work where there are sections of their responsibility. Besides, that they could identify existence or lack of tasks for themselves not only by means of the radio terminal if WMS – a system is applied, but also visually.

Rule No. 5. At the organization of a zone of set correctly consider the number of SKU

The rule is rather simple. Despite it, warehouses at which design designers do not understand that one nomenclature position is not one SKU meet.

Let's take for an example a warehouse of dairy plant. Within express audit of already ready project which should go to work employees say that 100 nomenclature positions should be stored in this warehouse. It is for this purpose provided in a zone of set of the whole 150 places. Now ask yourself a question: these 50% of occasional seats which were provided, really "additional"? All the matter is that if not to consider several moments, these occasional seats will not solve an assigned task at all.

It can become clear that the dairy plant works not only within production, but also performs independent delivery to the different regions which are in limits even of two weeks from plant. Respectively, there is a question what additional parameters can be considered at shipment of products? Of course, residual expiration date.

At the same time we understand that to the shops which are in close proximity with this plant we can ship products with a residual expiration date, for example, of 50% or less. If to speak about distant regions, then for them we will begin to ship a residual expiration date, for example, of 80%. In total in the specified example 3 conditions to shipment on a residual expiration date were revealed. At the same time, shipments happen to different conditions every day and without any time diversity.

Further we watch an average balance and we see, for example, that about 10 lots of products are once stored. It means that three conditions of shipment on residual term, most likely, will be crossed with those batches that are stored in a warehouse. As a result, in need of observance of FEFO that products evenly left a warehouse, we will receive increase in quantity of nomenclature positions (at recalculation on SKU approximately three times). So - 150 places for such warehouse are not with a stock at all, and even is not enough.

Rule No. 6. Implement buffering of a trade flow by transfer of loads between process areas

If to look at a warehouse in less detail, then during the whole day, work of sections will go practically with identical loading. It is about competently organized warehouse where the resource is expected each process area, and it is regulated depending on the current loading.

If to look narrowly in more detail and to pay attention how in such warehouse work is distributed in time, we will see that on one section it is executed by the periods quicker, than on another. To align this flow, between sections the buffer zone will be organized. So for example, after set products are put in a certain buffer section where she waits for the controller who will start its check.

Such buffer sections will quite often be organized in a spontaneous order, practically without calculation of their capacity in the anticipatory mode. In many cases, before a zone of control "patch" on which all will take is simply organized. It is better to get rid of similar practice. If buffering is implemented in a warehouse with an insufficient capacity of buffer zones, then - most likely - from these sections loads will get to the next process areas. If a warehouse high-intensity, then employees can be mistaken and allow very strongly a big resort which as a result will turn into a penalty and discontent of clients.

It is necessary to create the load graph on sections during the day, to determine buffer capacity taking into account the amendment on deviations, using a marking to limit section that employees could be guided and observe technology discipline visually.

Also it is necessary to pay attention to ergonomics of these buffer sections. It is not enough to deliver some number of pallets on a floor, to outline them and to tell that "put here". For example, in some warehouses of small-pieces products where set is made in trays, it is frequent between technology sections of enrollment and control the buffer is made out in the form of an end-to-end shelf rack. In that case - employees gathered products, on the one hand delivered in a shelf rack, on the other hand the controller performs extraction of a tray and performs the tasks. The possibility of continuous access to any load which within set came to this zone is so provided.

Some companies try to develop technology when the employee of a zone of acceptance takes a pallet, drives it on the cart to the avenue. At the same moment the narrow-passage rack is left by the piler, takes from the acceptor this pallet and it is lucky it on placement. It is natural that absolutely precisely it is impossible to synchronize work of these two units, even despite any assurances of third-party consultants or suppliers of WMS - systems. Just provide, in this case - or to the acceptor it is necessary to expect when the piler is released, or the piler should expect until the acceptor decides to bring to it a required pallet.

Rule No. 7. Detail each zone regarding need of the organization of additional service subbands which lack can affect the speed and quality of execution of operations

If you take about 80% of projects of warehouse complexes, then will see that the process area of control and repacking will simply consist of one section where - at best - the table and the computer is drawn.

In fact, control and repacking - transaction difficult. There can be most different situations. For example, if the controller detected shortage in the order - he fixes it and expects until to it deliver missing goods, or can rearrange the tray and a box which are in work in a waiting subband, having continued work with other objects. If the controller, repacking products, detected instead of five pieces, six or seven? It is natural that he cannot throw all the tasks, run and place these excesses in a cell where they were earlier. He places excesses in the corresponding subband, continuing the work and saving time. If the controller at himself on section identified defects, then the corresponding zone as the goods with suspicion on defects should be isolated from other products is also necessary.

This example needs to be projected on the organization of each process area of a warehouse as simple measurements sometimes show that up to 40% of time spent for a set of orders leave on preparatory transactions. It is search of a container, the cart, packing, and many other things. Investigate each operation on stages, then you have an opportunity to seriously increase performance.

Rule No. 8. Reduce to a minimum quantity of the used standard sizes of places in the storage area to exclude additional zoning

Why it is necessary to pay attention to this rule? Imagine the warehouse having about 300 thousand nomenclature positions and more than 30 standard sizes of places in a warehouse. Pallets of absolutely different standard sizes come to such warehouse. Let's assume that pallets one meter high at some point came. We unexpectedly made the decision to organize under them cells of the corresponding height. Further, to us pallets 1.5 meters high came, then - 2 meters, then - 2.25 meters. If under each height we try to build beams, we will receive strongly fragmented warehouse and if at some point "small" pallets leave a warehouse, we should rebuild spaces for big heights again.

Rather periodically to carry out the analysis of a trade flow regarding height of the pallets arriving and leaving from a warehouse to make the decision on the organization of places of different height.

As a result, than it is less at you standard sizes of places on height, especially universal is a warehouse in terms of placement of loads. So, for example, if to make all places in our example on 2.25 meters, then in them we will be able already to place also any other pallets. However, everything depends on a share which is occupied by pallets of these or those heights. The it is more, the need to think of selection of a separate zone of a warehouse under storage of this standard size is stronger to provide higher utilization coefficient of functional volume.

Rule No. 9. Change structure and purpose of zones of a warehouse if it is required by the current conditions

Problems of a warehouse can often be noticed even visually, having just visited it. For example, in a warehouse strongly fragmented set when the employee many times approaches one cell is conducted, and it should do several bypasses. At the same time, in parallel, in a constant duty there is a vymeshcheniye and replenishment. As a result transaction of set takes a lot of time.

In this situation, it is always necessary to look for the one and only reason because of which all this happens. In the specified example, fault to all is the insufficient capacity of a zone of set. The employee gathered loads at the first pass, then replenishment on other positions was made, he made a repeated bypass for completion of enrollment on the current volume of tasks.

If there is such situation, then carrying out restructuring of process areas of a warehouse is possible. Let's say if in a zone of set only pallet places, without shelves are used, it is possible to carry out the small analysis which will allow to select a large number of articles whose average speed of leaving allows to place them on shelves.

Thus, having delivered additional beams and having placed on them the load relating to group "C" on the volume of leaving and access rate we will receive reduction of labor costs in set, but increase in labor costs in replenishment. A task of the technologist of a warehouse - to find balance between amount of works on replenishment and a final stock of a zone of set that will allow a warehouse to function optimum within current limitations.

Some warehouses of low alcohol products, in view of serious between peak (seasonal) and annual average load, for a season are re-structured. The zone of detailed control actually cleans up, being transformed to an expedition shipment zone where there are goods expecting shipment in the nearest future. Control is executed at the expert level that allows - let and adjusted for a human factor, but to provide required intensity of shipments. The main rate becomes already on volumes, and here the price of an error is significantly less, than the missed profit at products underdelivery.

Rule No. 10. Do not rely when calculating the areas and volumes of zones of a warehouse on "magic coefficients"

On the Internet there is a set of the materials devoted to certain "magic coefficients" in which it is said, for example, that the zone of acceptance should make about 10% of the total area of a warehouse, and a set zone – about 20% of the storage area and so on. Take into account and read the justifications of such output which are applied to digits quite perhaps, but it must be kept in mind that any coefficient works only in the annex to specific technology, the area and a trade flow.

For each warehouse these values absolutely unique and if to you approve the return, then it - at least - "slyness", lack of competences, or the enlarged calculation not applicable for detailed design. Each zone of a warehouse is calculated under requirements of a specific trade flow. It is impossible to increase simply "And" on "In" and to receive the uniform answer to all questions.