Inheritance of Attribute Values

This document explains the different methods for inheriting attribute values within an order and between orders.

Outcome

Attribute values are based on inherited information either from the top level in an order-initiated chain of orders or from one or several material issues in a manufacturing order.

The inheritance is used to ensure that correct information is retrieved to a different order level.

The following tables are updated:

  • Order-based attributes (MOATTR)
  • Balance identity-based attributes (MIATTR)

Before you start

  • You must have defined attribute models with all attribute identities needed. These models must be connected to the items used.
  • The attribute identities to be used in the inheritance should have default handling defined.
  • You must have defined which materials in a product structure are to be used in the inheritance in ‘Product. Connect Materials/Operations’ (PDS002/F).

Description

Inheritance means transferring information within or between orders by using of attributes.

There are two types of inheritance:

  • Hard inheritance
  • Soft inheritance.

Hard Inheritance

Hard inheritance is used to ensure that the value of a specific attribute is automatically carried from a one level to another in a chain of orders. The value will always be the same on both levels and it is always updated from a single point, a controlling attribute. This applies upstream as well as downstream.

A hard inheritance consists of one inherited and one controlling attribute, both with the same attribute identity and a reference between them. In order for a hard inheritance to occur, the same attribute identity must exist on both levels.

For downstream inheritance, the value is only inherited from the top-level order to all order-initiated levels below where the same attribute identity exists. In a downstream inheritance there is no requirement that the same attribute identity exists on all levels. Downstream inheritance is valid for all order categories.

Upstream inheritance is only valid for manufacturing orders and the value is then inherited from a material to a product. Each attribute on a product can use its own hard inheritance, each based on different materials. There can only be one controlling attribute per attribute on the product. In order to find the controlling attribute, the performed material issues for the manufacturing order are verified in reporting date/time order. The first transaction found using the same attribute as the one on the product is set as a controlling attribute. If the controlling attribute in itself is hard inherited, then the reference is inherited rather than the value. This means that the hard inheritance can be stretched through multiple levels of manufacturing orders under the condition that the same attribute identity exists on each level of semi-finished products.

Soft Inheritance

Soft inheritance can only be activated for manufacturing orders. For manufacturing orders, inheritance (both hard and soft) will only be activated for materials that are set as inheritance controlling in ‘Product. Connect Material’ (PDS002/F). This will only be used at the receipt of a product from a manufacturing order.

Other transactions will use the normal default value handling, which means that you can enter a normal default value as well as using the inheritance within the same default setting.

Note that if no record for a default value exists for an attribute, it is assumed that it will use hard inheritance.

Soft inheritance is used to transfer information from material issues to the product by using numeric attributes. In soft inheritance, there will be no links between material and product. Changes to the inherited attribute values for the issued materials will not affect the related attribute values on products. Due to this, it is important that, when soft inheritance is used, the material issues are performed prior to the receipt of the product.

In contrast to hard inheritance, soft inheritance can inherit information from multiple material issues. This includes both issues from a single material item number as well as from multiple material item numbers.

Soft inheritance can be combined with formulas as well as information retrieved from fields on the component level (such as VMRPQT, issued quantity). If a formula is combined with soft inheritance, then the calculation will solely be based on information from the transaction history for the retrieved material issues. This means that item information like weight, volume and length is picked up from the material item number; the attribute values, quantities and so on are retrieved from the transaction history. If no field or formula is entered, then the inheritance will only be done if the same attribute identity exists on material and product. If no inheritance can be performed, the normal default value handling will be applied.

There will be no conversions of used units of measure of retrieved quantities, for example. Due to this, all used material issues should use the same U/M.

Calculation Options

The values in soft inheritance are calculated as follows:

  1. Total—A sum is stored; negative values are deducted from the sum.

  2. Average—This is calculated as ‘Total / Number of retrieved values’.

  3. Maximum—The maximum of the retrieved values is stored.

  4. Minimum—The minimum of the retrieved values is stored.

Note that the formula calculation is done per material issue and is done prior to the selection of which value is to be used. Also note that the comparisons respect the sign of the retrieved values.

Example

The transaction history contains material issues for one material belonging to the same manufacturing order. Materials A and B are inheritance coded in the product structure:

Material and Rep Time Quantity Attribute X Value
A: Time 1000 5 10
A: Time 1100 3 12
B: Time 1130 6 14

The result of the different inheritance settings:

Attribute X exists both on the materials and the product. Attribute Y is equal to reported quantity; the Field parameter in ‘Attribute Matrix. Enter Default Values’ (ATS030/E) is set to VMRPQT.

Inheritance Result Y Result X Comment
0 (hard inheritance) - 10 X: Value 10 since this is the first reported transaction
1 14 36
2 7 12

Y (8(5+3)+6)/2=7

X (10+12+14)/3=12

3 8 14 Y: Maximum per material number and not transaction
4 6 10 Y: Value=6 since the quantity is from the material line
Note: The average for the quantity is based on the information on the manufacturing order and not the transaction history. In this example, the quantity for material A is equal to 8 (5 + 3) and for B is equal to 6. There are two materials and therefore it is divided by 2.