Skip to main content
Skip table of contents

Classification and Numbering

Classifications usage

Classification used to set number:

The serial number will depend on use of number-giving classification or not in the database.

Number-giving Classification : All occurrences of the Items connected to this classification will be assigned a database unique number based on the classification + running number.

None number-giving Classification: All occurrences of the Items be assigned a database unique number based on the Item number + running number.

Read more Add Classification to the database

Classification used for additional sorting.

When you add a classifications to Systems, Items, or Rooms you will find an extra tab with the classification name in the navigation pane. When you select the “Classification” tab you will be able to add and navigate between different classification within the “Classification” tab. You will only see Systems, Items and Rooms that have been given the classification. In the example below you will see:

  • That the classification “OminClass 21” has been added.

  • Only the classification “21-04 00 00” have been added to a System Component.

System numbering

In our data model we have suggested that separate the System running number and the System Component running number using a colon. Number for a supply air System can look like this when number-giving classification is not used:



Number explanation


Item number

Item number that is given by where it is placed in the Item Group structure




System Component running number




System running number


Complete System Number

The System serial number is '01'. Identifying that this is the first System connected to the System Component.

System Component and Component Serial Number

Unique number

Components represent occurrences of an Item and will automatic get a serial number after the Item Classification. The Item classification and the serial number is absolutely unique in the database. 

Since the number/code is unique, we can use this as an address in the central processing System, flow balancing and documentation. 

System and Item Classification:

The Item can have:

  • System classification

  • Item classification.

  • Both System and Item classification

In all cases the Classification must be set on the item so that it can generate unique codes for the occurrences. 


When both an Item and a System Classification are assigned to an Item, the Item Classification will be assigned to the Item and System Classification will be assigned to the occurrence of the Item.

Classification determines if it is a System Component or a Component

Occurrences of Item with System Classification will be a System Component. Occurrences of Item without a System classifiation will be a Component

Example: Numbering

When we combine all these classifications, we have a human readable code that gives us a lot of information about a Component. 

Location (A01) - Building A floor 01
System Component (M.002) - Mechanical unit number 002, Air handling unit



Number explanation


Location code

Classification code for Building A Floor 01


System Component

Air handling unit. Mechanical unit number 002


System serial number

Supply air System. First system owned by System Component M.002

23-33 25 13 11


Customized Indoor Air Handling Units. Number from OmniClass 23


Occurrence serial number

First Occurrence of the Component 23-33 25 13 11

A01+M.002:01 - 23-33 25 13 11/001

Occurrence number

Complete Occurrence number


Component number form Primary system

In dRofus we can connect multiple systems. For example, the Component  "VAV-unit" can be member of:

  • Air distribution system

  • Electrical system (Circuit)

  • Signal system.

The Component can only inherit number from one of these systems. That's why you can set "primary system" for the Component in the connections in properties pane. You can change primary system for the component after it's created. By changing the primary system, you will also change the number/ID of the component.

Note that you also can set Primary System to an System Component, but this will not effect the number to the System Component

Set classification

Set Classification on Component and System Component

JavaScript errors detected

Please note, these errors can depend on your browser setup.

If this problem persists, please contact our support.