The terms are often encountered in BIM projects: level of development, level of detail and level of information. The terms are not defined in a law or standard, but are conceived to improve the communication within a BIM project. In practice, however, the terms tend to cause confusion. In order to avoid misunderstandings about the agreements made about the level of detail in the initial phase of the project, it is important to understand exactly what the three terms mean.
Level of development [LOD]
The level of development includes both the graphical representation of the family and the level of information linked to the family. Level of development is often abbreviated with LOD and is often mentioned in BIM-related documents such as the BIM protocol. The level of development is the most general term of the three and is less useful for detailed agreements.
Level of detail [lod]
When we talk about the level of detail, we're only talking about the graphical representation of the family. A family with a low level or detail, for example, has a simple geometric shape such as a cube or cylinder and will not contain any specified material. The level of detail, unlike the level of development, says nothing about the information that is linked to the family.
Level of information [loi]
Information plays an important role in a BIM project. The level of information is used to indicate the level of information linked to a family. A family with a very high level of information includes, for example, manufacturer-specific data sheets and maintenance instructions.
How to deal with LOD in a LEAN way
The three terms LOD, lod and loi can be helpful for making clear agreement with other parties in a project. Thinking beyond the level of development alone will prevent data (graphic or informative) being added to the model that is not used. For example, it can be quite useful for a project in which LOD500 (in connection with maintenance) is asked for example, to suggest to model the level or detail at a lower level than the level of information. It is important to describe in the BIM protocol what exactly is covered by the various levels of the loi, lod and LOD. In this way, it becomes clear which information really matters, what is expected from each party, and the collaboration can really take off.
