Variant tree
The variant tree (or variant list ) is an approach to the representation of variant structures in their equality and difference. The individual variants are represented in the variant tree by the simultaneity of elements or functions at the ends of the individual branches; these relationships can also be viewed as nodes and edges.
The tree structure is particularly suitable for displaying complex objects with a variable number of branches and variants in their overall context.
Reasons for the variant trees
Possible reasons for variant trees are:
- Associative thinking behavior when analyzing relationships
- Simplest structural form
- Self-explanatory
Variant tree and non-elements
In order to fully describe a variant tree in its variants, it is fundamentally necessary to also describe the elements that are not included. In order to obtain a consistent and complete variant tree, the description of all variants using an ideal Boolean algebra is useful and helpful, in which there is always a complement (non-element) for every set (element). There are binary variant trees that have only two disjoint elements on one branch, or multiple variant trees that have more than two elements on one branch, which are also disjoint and mutually exclusive. This means: if the variant tree is run through for a specific object, only one variant can be selected (= run through ) for each branch . become.
- Example: list of variants
| features | vessel | amount | colour | label | content |
|---|---|---|---|---|---|
| version 1 | bottle | 0.5 l | brown | With label | beer |
| Variant 2 | bottle | 0.5 l | brown | With label | Soda |
| Variation 3 | bottle | 0.5 l | green | without label | without |
- Example: features and characteristics
| features | vessel | amount | colour | label | content |
|---|---|---|---|---|---|
| Expression 1 | bottle | 0.5 l | brown | With label | beer |
| Expression 2 | without | without | green | without | Soda |
| Expression 3 | without | empty | without |
- Examples: rules
| Rule 1 | Not without a vessel |
| Rule 2 | Amount not without |
| Rule 3 | Color not without |
| Rule 4 | Color brown or green |
| Rule 5 | Label and (color brown or green) and (content of beer or soda) |
Variant tree or variant list
The tree structure quickly provides information on the same elements in different variants, which is not easy to see in table form. The tree structure, table list / pivot and rule list are the three common forms of representation of variance in variant management.
So far, there are few commercially available tools (Travis, Metus, etc.) and various consulting software on the market that have specifically specialized in tree structures in variant management. Overall, variant management is still a relatively new aspect of software development.
Due to the increasing number of variants, the configurable complex parts list has established itself in the automotive industry as a special form of variant parts list which, with the help of logical or Boolean expressions, assigns the "list elements" (parts, assemblies, etc.) to the higher-level object ( product (Economy) or assembly ). This is also known as relationship knowledge. These relationships can also be represented using a Venn diagram. The prerequisite for this is the definition of the product variants with the help of features that are also called equipment ( list of equipment features for motor vehicles ) in automobile construction. The features can appear loosely next to one another or have an orderly relationship to one another. It is particularly effective if the features form an ideal Boolean algebra , because this makes the representation of all variants very compact and the relationships between the variants can be checked for logical consistency or freedom from contradictions .
The Boolean expressions that appear in a complex parts list for the assignment of the various variants can also be saved as a binary or multiple search tree (see also AVL tree ), which enables particularly effective processing.
Individual evidence
- ^ W. Herlyn: On the problematic .... Hanser Verlag, Munich 1990, p. 64 ff.
- ^ W. Herlyn: PPS in automobile construction. 2012, p. 81 ff.
Simultaneities in the variant tree or variant lists
Within a branch of a variant tree, the elements arranged on it are referred to as simultaneities. In the work process, the elements of simultaneity are to be related and result in the branch or the [(variant)].
literature
- Florian Burgdorf: A customer and life cycle-oriented product family protection for the automotive industry . KIT Scientific Publ., Karlsruhe 2010, ISBN 978-3-86644-562-8 , Chapter 6.3, p. 152 .
- W. Herlyn: On the problem of mapping products with many variants in the automotive industry. VDI Verlag, Düsseldorf 1990, ISBN 3-18-145216-5 .
- W. Herlyn: PPS in automobile construction - production program planning and control of vehicles and assemblies. Hanser Verlag, Munich 2012, ISBN 978-3-446-41370-2 .