4D BIM Engineering Design adds time to a construction project, where a stage by stage process is analyzed and used in the construction sequence. This allows the various participants, Architects, Engineering Designers, Contractors, Sub-contractors etc., of a construction project, the ability to visualize the entire duration of a series of events and displays the progress of the construction project activities through the lifetime of the project. This approach has a very high potential to improve the project management and delivery of a construction project of any size and complexity.
5D BIM Engineering Design Incorporates costs: e.g. cost of materials in the construction process and that can affect the predecessor dimensions previously mentioned. Equipment may be changed due to cost and the volumetric dimension will vary from previously thought equipment.
6D BIM Engineering Design adds project life-cycle, facilities management/rooms information to the design which can affect all previously mentioned dimensions.
Arguably, this could include functionality in the BIM model, e.g. in a computer generated model, one can click a light switch and the light fixtures actually turns on, or flush a toilet and see how water runs in the pipes, all in a computer model. This is believed to be in the research phase or at its infancy.