This module can be applied for the simplest case where you are only interested in knowing the quantity of each product in your stock as for a complex warehouse(s) management case, where for example each product gets a specific location in the stock and upon delivery it needs to be picked at a certain location and the products need to be packed in boxes and put on a pallet.
Because of this huge difference in application, the main principles briefly will be explained first, whereafter we will dedicate one chapter on how to use the warehouse management in its simplest form. From the third chapter on, we will explain every step in more detail, allowing you to discover the full potential of the module.
In order to make it easy to move multiple products at once and pass that as an assignment to a warehouse operator, we use pickings that group these stock moves.
We want to categorize the pickings in picking types. As a warehouse manager you want to follow up the progress of the operations between the same (kind of) locations. E.g. by default, in the default warehouse, you will have 3 picking types: the incoming, internal and outgoing, but it is possible to create a picking type for all the packing operations that need to happen at the packing table. The Warehouse > All Operations dashboard allows to see the progress of the pickings for each picking type.
You might have a weird feeling talking about moving from location A to location B, even for deliveries and incoming shipments. That is because OpenERP uses a double-entry concept similar to double-entry accounting. In OpenERP you do not talk of disappearance, consumption or loss of products: instead you speak only about stock moves from one place to another.
To satisfy the need for a counterpart to each stock movement, the software supports different types of stock locations:
* Physical stock locations,
* Partner locations (suppliers and customers),
* Virtual locations as counterparts for production, inventory and scrap.
Partner locations represent your customers' and suppliers' stocks. To reconcile them with your accounts, these stores play the role of third-party accounts. Reception from a supplier can be shown by the movement of goods from a partner location to a physical location in your own company. As you see, supplier locations usually show negative stocks and customer locations usually show positive stocks.
Virtual locations as counterparts for production are used in manufacturing operations. Manufacturing is characterized by the consumption of raw materials and the production of finished products. Virtual locations are used for the counterparts of these two operations.
Inventory locations are counterparts of the stock operations that represent your company's profit and loss in terms of your stocks.
In OpenERP, locations are structured hierarchically. You can structure your locations as a tree, dependent on a parent-child relationship. This gives you more detailed levels of analysis of your stock operations and the organization of your warehouses.
A warehouse represents the building where we stock our goods. In case of multiple warehouses, you can enter the warehouse on your purchase orders and sale orders, such that your transporter knows where to deliver or pick it up. That is why a warehouse also has an address and a name.
A warehouse corresponds also to a location. As the locations are hierarchical, OpenERP links a warehouse with one parent location that contains all the different sublocations in the warehouse.
A product can be MTO or MTS. When a product is handled MTO, it means we will handle each order (e.g. sale order) individually and procure what is necessary, separately for every order. When a product is handled MTS, we wait until there are sufficient orders and then we order everything at once taking into account a minimum stock (or a stock forecast) into account. In OpenERP, we can automate minimum stock rules through orderpoints as shown in the next chapter.
When we start to create a move, it will be in draft state. This means, it will have no influence on even the virtual stock of the product. It is only when we confirm the move that we make clear to the system that this move will be executed and should be taken into account for ordering new products. The next state will however be different according to the scenario. For example, if the product is MTO, in the stock location, it will wait for a specific purchase order and will have the Waiting Another Move state. In case of an MTS product, the move will be configured as such that it will look for available stock in the source location itself and it will go to the Confirmed state.
In these states it is possible to do "Check Availability". If it can find the necessary stock, the state goes to Assigned. In this state it is possible to effectively execute the move and transfer the products. Incoming shipments are automatically available. Effectively executing the move, brings it to the done state and makes it adapt the stock available on hand. (quantity on hand)
Normally, the picking associated to the move, will have the same state as it moves, but the picking can also have a partially available state. It is possible that some products in the picking are available and some are not. On a sales order or delivery order picking, you can specify if you want your customer to be delivered as soon as possible when only a part of the products is available (partial delivery) or only all at once when everything is available (in order to save on transport costs for example). So, if you can do a partial delivery, the picking state will be partially available when only some of the products are available.
Procurements represent needs that need to be solved. For example, every sales order line will create a procurement in Customers. This will be solved by a move for the delivery, which will, in case of a MTO product in buy configuration, create a new procurement (need) in Stock, which will be solved by a purchase order.
It is not required however, to have this need in stock created by a move. In case of MTS, the move will not create a procurement (need), but the the procurement will originate from an orderpoint created for this product in stock.
An orderpoint applies the following rule: if the virtual stock for the given location is lower than the minimum stock indicated in the rule, the system will automatically propose a procurement to increase the level of virtual stock to the maximum level given in the rule. We underline that the rule is based on virtual quantities and not just on real quantities. It takes into account the calculation of orders and receipts to come.
You can also set multiple quantities in the minimum stock rules. If you set a multiple quantity of 3 the system will propose procurement of 15 pieces, and not the 13 it really needs. In this case, it automatically rounds the quantity upwards.
Pay attention to the fact that the maximum quantity is not the maximum you will have in stock. If we take the following situation: a company has 10 pieces of product with minimum stock rules defined for this product by Min quantity = 10, Max quantity = 30 and Qty multiple = 12. If an order of 2 pieces comes, a purchase of 24 pieces order will be executed. The first 12 pieces will be ordered to reach the minimum quantity and the other 12 to reach the maximum quantity. At the end, the stock of this product will be equal to 32 pieces.
In order for the orderpoint to create the procurement, we need to launch the scheduler. This can be done manually in Warehouse > ..., but will normally be automated by a scheduled action. (by default it is automated on a daily basis)
Suppose you have multiple lines in your sales order, then you want one delivery order with all the lines of the sales order. In order to do that, we group the different procurements of this sale order into the same procurement group we create for the sales order. That way the moves of a delivery order are together.
Suppose we have a little Apple Store. The warehouse will be Apple Store and we manage only one location (no child locations). We put a minimum stock of 10 iPad mini and 5 iPod nano. We don't have stock for iBooks, but when a customer wants one, he can order one and will get it after a week.
We will create an orderpoint for every product with minimum stock. These orders could also be created by the point of sale. The maximum of the orderpoint, we will take 15 and 10 and . This orderpoint will need to be created in the Stock location.
In the following chapters, we go a little deeper into the mechanisms behind the warehouse management. In this chapter, we handle the stock moves. Stock moves are not only the basic notions through which stock is moved, but can be chained and will determine their picking. Chained moves are not only necessary in case of an MTO product, where the delivery waits for the specific incoming shipment, but for example also in multiple step in or out or when resupplying from other warehouses. We will describe how pull and push rules are applied to created such chained moves.
When you want to give an assignment to a warehouse operator manually, you will create a picking and create the moves in it by specifying the different products and quantities. When confirming a sale order however, OpenERP will create the moves automatically. In these cases, it will create the stock moves without picking first. In a second step, they will be attributed to an existing picking or a picking will be created.
In order to assign the move to a picking, OpenERP will check if the move was assigned a picking type (e.g. Your Company: Delivery Orders) and if it does, it will search for a picking to assign the move to. This picking should be in the right state, picking type, procurement group (=group of procurements related to e.g. the same sale order) and source and destination. If no picking can be found, it will create a new one.
This mechanism allows for a lot of flexibility when for example some products have to be packed and some don't. That way, the packing order will still group the moves that need packing from the sale order and the direct moves will be grouped in a separate picking also. For the delivery order, everything will be together in one picking again.
A picking is almost entirely determined by the moves in it. The state depends on the moves and the picking type, the source and destination location are those of the moves. The scheduled date is calculated as a minimum date for the stock moves.
The other states depend however also on the move type. The move type determines whether the customer expects to get all products of a picking at once (=all at once) or he wants it delivered to him as fast as possible. (=partial) This move type can be determined manually, or can e.g. come from a sale order where it will be passed through the procurement group.
In case of partial, a special state exists: partial availability. It is possible that a move is in the confirmed / waiting state, but has partially some stock reserved. This move will still be in the waiting/confirmed state, but have a flag partially available. In that case, the picking will not stay in the confirmed/waiting state but go to the partially available state, which makes it possible to deliver the goods partially. A picking is also partially available when some moves are assigned and others have no stock at all reserved.
Sometimes a move does not have a picking type. This means it will not be assigned to a picking. This is the case for inventory corrections and moves in and out of production.
A rule that trigger another stock.move based on a stock.move based on its destination location.
Example: When products arrive manually in the “Input” location, you want to move them to “stock” directly with a push rule.
So, when a stock.move “Supplier → Input” is confirmed, this rule will create another stock.move: “Input → Stock”. It allows for 3 modes: automatic (the second operation will be validated automatically), manual (the second operation must be validated manually), manual no step added. (the destination of the first move is replaced instead of creating another stock.move.
Push rules should typically only be used on incoming side when a purchase order is created manually and the goods need to be transferred to stock.
Pull rules are not the opposite of push rules! It’s very different as push rules impact moves and pull rules impact needs. (procurements) It is actually better to call them procurement rules. It is however true that the push rules are applied on the destination location and pull rules on the source location.
When a stock move is confirmed and its procurement method is 'Advanced: Apply procurement rules', it will create a procurement in the source location for the quantity of the move. To fulfill this procurement, a procurement rule needs to be applied on this procurement. There are several types of procurement rules with different results: move products from another location to the source location, purchase to the source location, produce towards the source location.
A procurement does not need to be created by a stock move. A user can create a procurement manually and from v8, a sale order creates a procurement in Customer. When we run this procurement, it will create the delivery order based on the application of procurement rules.
It is however possible that the procurement goes into Exception when no procurement rule can be found or when it is not possible to apply the rule (e.g. no supplier defined for the product). When the products are no longer necessary, it is possible to Cancel the procurement.
By default, the JIT scheduler is installed and the system will try to check the procurement immediately when it is confirmed. If this would give performance issues, it is possible to uninstall this and then it will only run the procurements immediately generated by the sales order. This will result in a delivery order, but the procurements generated by the delivery orders, will not be run. This will however be done by the Scheduler.
Whether a confirmed stock move created a procurement in the source location and applied the procurement rules, depends on its procurement method. It has to be 'Advanced: apply procurement rules and wait for availability'
When a user creates a stock move in a picking, the stock move will have its procurement method 'Default: Take from stock when available'. This means it will not create a procurement in the source location created to the move and will try to find the products in the available stock of the source location. This is also the most logical thing to do when some goods need to be transferred internally for example to put not much requested products to the back of the warehouse.
If the user chooses however to change the procurement method to 'Advanced: Apply procurement rules', a procurement will be created in the source location. And for example, creating a delivery order could lead in the simplest case (with purchase) to creating a purchase order the delivery order will be waiting for. This is also only interesting for internal or outgoing pickings. Incoming shipments do not need to reserve stock, so they are always 'Default: take from stock'
So, on itself, this is not too interesting. However, when a procurement rule creates another move, it can determine the procurement method of the new move. In other words, it can determine if the new move will again look for procurement rules or will take from the stock.
This makes it possible to create long chains. For example, an MTS product with pick pack ship, will start with the confirmation of a sales order. This will create a procurement, which will create a move from Output to Customers with procurement method "Advanced: Apply procurement rules". This will create procurement in Output. This will continue like this until the procurement in Pack creates a stock move, which will have "Default: Take from stock" instead.
<< Illustrate one from the chains from the Google Doc>>
<!--When we create a sale order for an MTO product, a procurement will be created in Customers. The rules will tell that this should be solved by a move with procure method "Create Procurement" from Stock to Customers. This move will create a procurement in its source location that will be solved by a rule telling to buy from a supplier. That way a chain is created of moves waiting for each other. -->
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Chained Moves and States
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It is clear that the push and procurement rules allow to create long chain of moves. When we talk about the chaining of moves we distinguish for a move between:
* Destination move: The next move in the chain starting in the destination location of this move
* Original moves: The previous move(s) in the chain all arriving in the source location
When a move has original moves, it can only reserve stock that passed the original moves. This is also why the state for these moves will go to Waiting Another Move instead.
A move can only have one destination move, but multiple orginal moves. Suppose you have two moves that are chained. When the first one is split, the second one has 2 original move and both moves have the same destination moves.
If the second one is split however, the split move, won't have any original moves on itself, but will check if it has not been split from a move with original moves, and might as such also take the Waiting for Another Move state.
<!--Chained moves can be created with procurement rules, but another type of rule exists. Push rules can be defined on destination locations. When a move is confirmed and a push rules is defined on its destination location, it will create a move from the previous destination location towards a new destination location. These rules come in handy when creating purchase orders manually and we want to receive in an Input location at the gates first, before transferring them to the stock in the racks. Push rules will not be applied when the move was created from procurement rules. On outgoing side, push rules will normally not be used.
One move can have several original moves, but only one destination move. When confirming a move with original moves (or split from a move with original moves), the move will go to the waiting state (Waiting Another Move) as it will wait for its previous moves to be executed. -->
The checkbox MTO in the product form is actually a procurement rule that may be applied. This means that the delivery order from stock will be created with procurement method "Advanced: apply procurement rules" instead of "Default: take from stock".
All procurement operations (that is, the requirement for both production orders and purchase orders) are automatically calculated by the scheduler. But more than just creating each order, OpenERP plans the timing of each step. A planned date calculated by the system can be found on each order document.
To organize the whole chain of manufacturing and procurement, OpenERP bases everything on the delivery date promised to the customer. This is given by the date of the confirmation in the order and the lead times shown in each product line of the order. This lead time is itself proposed automatically in the field Customer Lead Time shown in the product form. This Customer Lead Time is the difference between the time on an order and that of the delivery.
To see a calculation of the lead times, take the example of the cabinet above. Suppose that the cabinet is assembled in two steps, using the two following bills of materials.
The SIDEPAN is made from an order using the workflow shown. The WOOD002 is purchased on order and the other products are all found in stock. An order for the product SHE100 will then generate two production orders (SHE100 and SIDEPAN) then produce two purchase orders for the product WOOD002. Product WOOD002 is used in the production of both SHE100 and SIDEPAN. Set the lead times on the product forms to the following:
Lead Times
Product Code
Customer Lead Time
Manufacturing Lead Time
Supplier Lead Time
SHE100
30 days
5 days
SIDEPAN
10 days
WOOD002
5 days
A customer order placed on the 1st January will set up the following operations and lead times:
Delivery SHE100: 31 January (=1st January + 30 days),
Manufacture SHE100: 26 January (=31 January – 5 days),
Manufacture SIDEPAN: 16 January (=26 January – 10 days),
Purchase WOOD002 (for SHE100): 21 January (=26 January – 5 days),
Purchase WOOD002 (for SIDEPAN): 11 January (=16 January – 5 days).
In this example, OpenERP will propose placing two orders with the supplier of product WOOD002. Each of these orders can be for a different planned date. Before confirming these orders, the purchasing manager could group (merge) these orders into a single order.
Security Days
The scheduler will plan all operations as a function of the time configured on the products. But it is also possible to configure these factors in the company. These factors are then global to the company, whatever the product concerned may be. In the description of the company, on the Configuration tab, you find the following parameters:
Scheduler Range Days: all the procurement requests that are not between today and today plus the number of days specified here are not taken into account by the scheduler.
Manufacturing Lead Time: number of additional days needed for manufacturing,
Purchase Lead Time: additional days to include for all purchase orders with this supplier,
Security Days: number of days to deduct from a system order to cope with any problems of procurement,
<< Orderpoints will also create procurements and have a different effect on the dates >>
In the previous chapter, we talked about procurement rules and how they were applied. We have not talked yet about when these procurement rules can be applied and how to configure them.
A lot of Warehouses have input docks and output docks or have a packing zone where people want to repack the packages for the customer. This can become quite complex and in order to manage this better, we group procurement rules and push rules into routes before having them applied to product, product categories, warehouses, ...
Using these routes is simple as you just need to select them on e.g. a product or product category, but configuring them correctly is a little more difficult. This is the reason why OpenERP will create the necessary routes automatically when you create a new warehouse. Configuring the warehouse can then be a simple as choosing two step incoming and 3 step delivery, will always be supplied from warehouse B, will be purchased, ...
If they can be applied on these models can be specified on the route itself. For example, you could create a route 'buy' with the purchase procurement rule from stock in it allowed to be selected on Product Category. Then you could go to the product category e.g. Purchased Goods and add it there. When a procurement is made in stock for the products in this category, the system will try to create purchase orders for it.
When a sales order creates a procurement it passes some useful information to it. First, a sales order has a warehouse where the goods need to be picked up. This warehouse will be copied on the procurement. For example, when you have a procurement in Customers, but you know it has to be delivered from Warehouse WH, it can add a route with a procurement rule from WH/Stock to Customers and it will not apply a procurement rule from WH2/Stock to Customers. Second, it is possible to supply an extra route on the sale order line itself. This can come in handy when you decide on the sale order what route to follow e.g. if you sometimes decide to do dropshipping, you could enter it there. These routes are copied on the procurement related to the sale order line.
These routes on the procurement itself can also come in handy when the procurement can not find a suitable rule. By adding a route, you can solve the procurement according to the situation. (e.g. a certain product needs to be manufactured sometimes or bought sometimes)
If in any of these cases, multiple rules are found, it will select the rule with the highest sequence. This sequence can be changed in Warehouse > Routes (drag/drop the lines). Normally, this will play almost no role.
Actually, when you select MTO on a product, this is a route that is chosen. As in the basic configuration, it is defined on the product. (it is shown in the product form in a special widget that shows all the possible elements it could have in the one2many and you can select them) As such, this route will be chosen over the standard route and will have a rule that puts procure method "Create Procurement on Source" to stock. In the route MTO all such rules for all warehouses will be put in the standard configuration.
The reason behind such a configuration is that in most situations, the routes followed through the warehouse are the same for almost all products. The exceptions on it can be defined for certain product categories or products. Some things like MTO or buy/manufacture might be better to put on product level. And then it is still possible that you change your mind on the sales order line.
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How does the system choose the correct push rule
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Searching for a push rule is quite similar as for the pull rule. It will however just search for all the rules in the routes of product and product categories and take the rule with the highest sequence. (???)
When you activate setting <<Activate push/pull rules >> and go to Warehouse > Warehouse and select a Warehouse (or create a new), you will have a simplified way to configure these routes without worrying about its complexity.
For the incoming and outgoing shipments, you can supply how many steps are needed to receive or ship goods. This allows you e.g. to receive at the docks, and move the goods later on into a precise location in your racks. It can also be interesting to do some quality control. For shipping, you can also put your products at the gates first, but you might also want to package them at a separate location before bringing them at the gates. These routes will be directly related to the warehouse.
If you check Purchase or Manufacture to resupply this warehouse, if a product is manufacture/buy, it will also be able to buy/manufacture from/in this warehouse.
When you put a Default Resupply Warehouse, goods will always be supplied from this other Warehouse.
You can choose multiple resupply warehouses. These are selectable on the product / product category. This is used when some products are supplied from one warehouse and others from another.
The Incoming shipments and Outgoing shipments routes are bundled into routes that are on the warehouse. So, if you choose that warehouse, it will choose the route by default. The incoming routes will also have the push rules associated with them.
Also crossdock is added as a route to the warehouse. This can be added on specific products and product categories that upon arrival are almost immediately transferred to the customer. (might be mostly the case with mto products)
When the state of a move needs to pass from confirmed/waiting to assigned and the move is not an incoming shipment, the necessary stock (=quants) needs to be reserved.
* If there are no original moves, it can take from the source location, but only if this stock has not been reserved on other moves. If the user would want to take from other moves, he can unreserve those.
* Also in case of returned moves, the system will check if the stock was moved by the move it was returned from.
* When choosing the stock, we need to take into account the removal strategy.
A different removal strategy can be defined by product category and location. For example, for a certain category of products LIFO (Last In First Out) could be chosen when taking products from its stock location.
Quants (stock) can be put in a package and a package can be put in another package. The same hierarchical structure can be used as for locations. When pack A is put in pack B, its full name becomes PACK B / PACK A.
Lots are always linked to a certain product and can be put as being required depending on the incoming/outgoing/full traceability selected on the product. If in a picking you do not select a lot, it can take any lot (or even without lot). If you select a lot, it has to take it.
In order to define the operations that can be proposed / executed by the bar code interface, we create / process pack operations. The stock moves itself will tell nothing about (from) which package / location/lot to take, in which location / package to put the goods. That is the job of the pack operations.
If a picking will be processed by the bar code scanner, OpenERP will propose the pack operations that need to be executed. If it is an incoming shipment, it will be based on the moves, otherwise it will use the stock that has been reserved already.
The putway strategies are similar to the removal strategies, but determine for the original destination location a child location where the goods should be deposited (instead as for the source location). By default, there is no putaway strategy defined on the destination location. In that case, the goods will be deposited in the destination location of the move. In the stock module, there is one putaway strategy: fixed location. For each such strategy you can also specify the related location. Of course, based on this, custom developments make it possible to implement the putaway strategy you want (as it is applied on all of the stock being moved at once).
For the reserved stock, OpenERP will try to find as many packages (and as high-level) as possible for which the stock is entirely reserved and the destination location is the same for every piece of stock. That way, the operator knows he can simply move the package to the destination location, instead of having to open the box and split the quantities.
Some pallets with product A and some mixed pallets with product A en B are placed at the gates and need to be moved to stock. A picking proposes to move all products A and B to stock. Product A has loc A as fixed location putaway strategy and product B has loc B as fixed location. In the pack operations, OpenERP will make an operation by pack for all pallets with only product A all to the loc A. For the mixed pallets, it won't be able to make one pack operation. It will say: move the product A from the mixed pallet to loc A and move the product B from the mixed pallet to loc B.
If we want to use a certain piece of stock on another picking instead of the picking selected, we can unreserve this piece of stock by clicking on the Unreserve button of the picking.
It is however possible that during the pack operations, the guy has chosen the stock from another location. In that case, other quants need to be reserved also. When processing this picking further on, the system will unreserve the stock and do the reserve process again, taking into account the created pack operations from the bar code scanner interface.
We need to check if the pack operations cover all moves and opposite. If there is more of a product transferred in a pack operation than in the moves, an extra move needs to be created in the picking and set to done. When there is less product in the pack operation than in the move, a backorder needs to be created with those moves and the original move might be split with a part going into the backorder.
In order to do this matching, the system will try to match with stock reserved for a certain move. It will loop through the pack operations and see if it can find the necessary stock it can match. That way it will match quantities from the reserved stock move on the quant with the operation.
If not everything could be matched with the reserved stock (e.g. an incoming shipment, this is always the case for the entire picking) it will match the remaining quantities on the moves with those of the packing operations.
<< Need to tell about partial availability here? >>
This function can also be used to check the effect of the current pack operations, but tell also if the reservation is actually used or not. If not, when transferring, it will have to rereserve the quants. (unreserve + reserve)
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Actual transferring
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If there are pack operations, it will look the matching, find the quants accordingly and move them.
If not, it will find the quants based on the moves only.
It is still possible that upon transferring for an internal shipment or delivery, the necessary quants or stock can not be found. In that case, it will create negative stock (negative quants).
When later on, a move brings in some goods that correspond to this negative stock, the quant can be reconciled with it. This will however not happen if this incoming quant has a chained move to another location. It is only when you force assign a move with original moves that it can also take from the regular stock (so not coming from its original moves). It will however not assign this stock before actually doing the transfer.
When you cancel a procurement, it will cancel everything in the backwards direction. When you cancel a move itself, it will cancel in the forward direction.
This will happen only if the move has the attribute 'Propagate Cancel and Split' set to true. Also, when a procurement rule (or a push rule) is applied to create another move, it will copy its 'Propagate Cancel and Split' on the move.
When you start using OpenERP, you might have an inventory to start from. (Starting Inventory) You will enter all the products that are in the warehouse and OpenERP will put them in this position. When you validate this inventory, OpenERP will create the necessary stock moves.
It is possible that operations in the warehouse are not well registered and the stock in OpenERP does not correspond exactly to the physical stock in the warehouse. Of course, you do not want this to happen, but errors do happen and a way to solve these mistakes, is to check the inventory once and a while.
You can decide to do a certain product or a certain location. So, you are not required to do all the invento
