18 January 2018
These terms are frequently encountered in BIM projects: level of development, level of detail and level of information. The terms have not been laid down in an act or standard, but have been devised as a means to help communication within a BIM project run more smoothly. In practice, however, it seems that the terms do, in fact, cause some confusion. To avoid any misunderstandings on the agreements that are made at the level of detail in the beginning phase of the project, it is important to understand what exactly the three terms mean.
Level of development [LOD]
The level of development comprises both the graphic representation of the family as well as the level of the information that is linked to the family. Level of development is often abbreviated to LOD and is often referred to in BIM-related documents such as the BIM protocol. The level of development is the most general term of the three and less useful for detailed agreements.
Level of detail [lod]
When we speak of the level of detail, we are only referring to the graphic representation of the family. A family with a low level of detail has, for example, a simple geometric shape such as a cube or a cylinder and will not contain any specified equipment. Unlike the level of development, the level of detail says nothing about the information that is linked to the family.
Level of information [loi]
Information plays a crucial role in an BIM project. The level of information is used to indicate the level of the information that is linked to the family. A family with an extremely high level of information comprises, for example, manufacturer-specific data sheets and a maintenance instruction.
Taking a LEAN approach to LOD
The three terms LOD, lod and loi are aids for making good agreements with the other parties in the project. Thinking beyond the level of development avoids data (graphic or informative) being added to the model that will not be used. For example, in a project that requires LOD500 (in relation to maintenance), it is quite conceivable to propose modeling the level of detail at a lower level than the level of information. It is important to describe in the BIM protocol what exactly falls under the various loi, lod and LOD levels. This makes it clear which information is really important, what is expected of each other and the collaboration can really begin.