Confirmation by Selecting Products Waiting Product Routing

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21.2 Bills of Materials

21.2.1 Use of Bills of Materials

Bills of Materials are documents that describe the list of raw materials used to make a finished product. To illustrate the concept of specification you are going to work on a cabinet where the manufacturing plan is given by the figure Plan of construction of a cabinet . Figure 21.1: Plan of construction of a cabinet The cabinet is assembled from raw materials and intermediate assemblies: Table 21.1: Product Definitions before defining Bills of Materials Product Code Description ARM100 Cabinet PANLAT Wooden Side Panel PANA100 Rear Panel PROFIL Metal Strut ETA100 Shelf PLET100 Shelf Panel BOIS002 Wood Panel BOIS010 Wood Panel TAQ000 Panel Pins LIN040 Lintel To describe how to assemble this cabinet, you define a bill of materials for each intermediate product and for the final cabinet assembly. These are given by the table below. Table 21.2: Bill of Materials for 1 ARM100 Unit Product Code Quantity Unit of Measure PANLAT 2 Unit PANA100 1 Unit PROFIL 4 Unit ETA100 3 Unit 295 Table 21.3: Bill of Materials for 1 ETA100 Unit Product Code Quantity Unit of Measure PLET100 1 Unit TAQ000 4 Unit Table 21.4: Bill of Materials for 1 PLET100 Unit Product Code Quantity Unit of Measure BOIS010 0.083 m2 Table 21.5: Bill of Materials for 1 PROFIL Unit Product Code Quantity Unit of Measure LIN40 0.25 m Table 21.6: Bill of Materials for 1 PANA100 Unit Product Code Quantity Unit of Measure BOIS002 0.25 m2 Table 21.7: Bill of Materials for 1 PANLAT Unit Product Code Quantity Unit of Measure BOIS002 0.083 m2 The bills of materials are then used by the software to calculate the raw material needs based on the requirements of the finished products. Then if you want to manufacture 10 cabinets, the system can calculate what will be consumed: Table 21.8: Total Quantities Product Code Quantity Unit of Measure BOIS002 0.416 2 0.083 + 0.25 m2 LIN040 1 4 0.25 m BOIS010 0.249 0.083 3 m2 TAQ000 12 3 4 Unit Tip: Bill of Materials To see the bill of materials in tree view, use the menu Manufacturing → Master Data → Bill of Materials then select the product and click on action Bill of Materials Structures. Figure 21.2: Bill of Materials structure Use the menu Manufacturing → Master Data → Bill of Materials and click on New button to define a new bill of materials. 296 Figure 21.3: Screen defining a Bill of Materials In the area below the bill of materials you should set the finished product, which will be manufactured or assembled. Once the product has been selected, Open ERP automatically completes the name of the bill of materials and the default Unit of Measure for this product. The type of BoM BoM Type : Phantom or Normal and the Routing field will be described in more detail later in the chapter. After this you can select the raw materials that are used in the manufacture of the finished product. The quantities are set out in a report based on the quantities of finished product and the quantities needed to produce them from the bill of materials. The second tab, Revisions, is used to set down all the changes made to the bill of materials. After each change you can specify a revision number and some notes on the modifications you carried out. Note: Simplified View The Revisions tab is only visible if the user works in the Extended View mode which means that the user must belong to the group Usability Extended View . Figure 21.4: Revisions of a Bill of Materials In the third tab, Properties, you can put a free text reference to a plan, a sequence number that is used to determine the priorities between bills of materials, dates between which a bill of materials is valid, and values for rounding and product efficiency. 297 Rounding is used to set the smallest Unit of Measure for expressing the quantities of the selected product. So if you set the rounding to 1.00 you will not be able to manufacture half a piece. The Efficiency of the product lets you indicate the percentage you lose during manufacture. This loss can be set for the finished product or for each raw materials line. The impact of this efficiency figure is to reserve more raw materials for manufacture than you would otherwise use just from the Bill of Materials calculations. The final part of the third tab lets you set some properties for the product’s manufacturing processes. These will be detailed further on in the chapter in the section on configurable products.

21.3 Multi-level Bills of Materials

In Open ERP each line of a bill of materials may itself be a bill of materials. So you can define BoMs with several levels. Instead of defining several BoMs for the cabinet in the figure Plan of construction of a cabinet you could define the single bill of materials below: Table 21.9: Single Bill of Materials for 1 ARM100 Unit Product Code Quantity Unit of Measure ARM100 1 Unit PANLAT 2 Unit BOIS002 0.166 m2 PANA100 1 Unit BOIS002 0.25 m2 PROFIL 4 Unit LIN040 1 m ETA100 3 Unit PLET100 3 Unit BOIS010 0.249 m2 TAQ000 12 Unit Open ERP behaves differently depending on whether the bill of materials is defined in several small BoMs each on a single level or in one BoM tree-structured on several levels. So if you select a BoM using intermediate products that automatically generates production orders based on calculated requirements, Open ERP will propose manufacturing an intermediate product. To manufacture a cabinet, you would create 6 production orders: Table 21.10: Production Order Product Code Quantity Unit of Measure PLET100 3 Unit BOIS010 0.249 m2 Table 21.11: Production Order Product Code Quantity Unit of Measure ETA100 3 Unit PLET100 3 Unit TAQ000 12 Unit Table 21.12: Production Order Product Code Quantity Unit of Measure PROFIL 4 Unit LIN040 1 m Table 21.13: Production Order Product Code Quantity Unit of Measure PANA100 1 Unit BOIS002 0.25 m2 298 Table 21.14: Production Order Product Code Quantity Unit of Measure PANLAT 2 Unit BOIS002 0.17 m2 Table 21.15: Production Order Product Code Quantity Unit of Measure ARM100 1 Unit PANLAT 2 Unit PANA100 1 Unit PROFIL 4 Unit ETA100 3 Unit In the case where a single bill of materials is defined in multiple levels, a single manufacturing order will be generated for each cabinet, including all of the sub-BoMs. You would then get the following production order: Table 21.16: Single manufacture from a tree- structured BoM Product Code Quantity Unit of Measure ARM100 1 Unit BOIS002 0.17 m2 BOIS002 0.25 m2 LIN040 1 m BOIS010 0.249 m2 TAQ000 12 Unit

21.3.1 Phantom Bills of Materials

If a finished product is defined using intermediate products that are themselves defined using other BoMs, Open ERP will then propose the manufacture of each intermediate product. This will give several production orders. If you only want a single production order you can define a single BoM with several levels. Sometimes, however, it is useful to define the intermediate product separately and not as part of a multi-level assembly even if you do not want separate production orders for intermediate products. In the example, the intermediate product ETA100 is used in the manufacture of several different cabinets. So you would want to define a unique BoM for it even if you did not want any instances of this product to be built, nor wanted to re-write these elements in a series of different multi-level BoMs. If you only want a single production order for the complete cabinet, and not one for the BoM itself, you can define the BoM line corresponding to product ETA100 in the cabinet’s BoM as type Phantom. Then it will automatically put ETA100’s BoM contents into the cabinet’s production order even though it is been defined as multi-level. This way of representing the assembly is very useful because it allows you to define reusable elements of the assembly and keep them isolated. If you define the BoM for the ARM100 cabinet in the way shown by the table below, you will get two production orders when the order is confirmed, as shown in the tables below that. Table 21.17: Definition and use of phantom BoMs Product Code Quantity Unit of Measure Type of BoM ARM100 1 Unit normal PANLAT 2 Unit normal PANA100 1 Unit phantom PROFIL 4 Unit phantom ETA100 3 Unit phantom 299 Table 21.18: Production Order from phantom BoMs Product Code Quantity Unit of Measure ARM100 1 Unit PANLAT 2 Unit BOIS002 0.25 m2 LIN040 1 m BOIS010 0.249 m2 TAQ000 12 Unit Table 21.19: Production Order from normal BoM Product Code Quantity Unit of Measure PANLAT 2 Unit BOIS002 0.17 m2

21.3.2 Assembly Bills of Materials

Note: Sales Bills of Materials In some software this is named a Sales Bill of Materials. In Open ERP the term assembly is used because the effect of the bill of materials is visible not only in sales but also elsewhere, for example in the intermediate manufactured products. Assembly bills of materials enable you to define assemblies that will be sold directly. These could also be used in deliveries and stock management rather than just sold in isolation. For example if you deliver the cabinet in pieces for self-assembly, set the ARM100 BoM to type Assembly . When a salesperson creates an order for an ARM100 product, Open ERP automatically changes the ARM100 from a set of components into an identifiable package for sending to a customer. Then it asks the storesperson to pack 2 PANLAT, 1 PANA100, 4 PROFIL, 3 ETA100. This is described as an ARM100 not just the individual delivered products. Example: Large distributor As an example of using these assemblies, take the case of a supermarket. In a supermarket, you can buy bottles of cola individually or in a pack of 6 bottles. The pack and the bottles are two different products and the barcodes used are also different. But customers have the right to open a pack and extract some bottles to take them individually to the checkout. The supermarket can not track its stock in packs and bottles any more, but only individually in bottles. So you can define a bill of materials for sale which defines a pack as an assembly of 6 bottles. Then when you have sold a pack, you can find a pack on the invoice or bill of sale but the associated stock operation will still be 6 bottles. In the case of this assembly, this is not a production order to transform the product. The transformation is done directly between the order and the set. Note: Assemblies and Purchases The use of assemblies for selling to customers has been described here, but this functionality works just as well for purchases from suppliers. So in the example of a supermarket, you can buy cola in packs and the storesperson will see a number of bottles at goods in reception.

21.3.3 Configurable Bills of Materials

In Open ERP you can define several bills of materials for the same product. In fact you can have several manufacturing methods or several approved raw materials for a given product. You will see in the following