Behandling af systemelementer

Processing of System Elements

This step is a lot like the prior step. Instead of processing the location elements of the BIM model, now the system elements are being processed. To start with the user must know which type the system elements of the model are. For now the processing can only handle one system type at a time. 

All elements describing building parts should usually have class identification code in following format:

• CCS: A.AB
• SfB : (24)1
• NS: 234
• Unicode: Various formats

Here is a code based on international standards. These codes define the type of the object, not the exact code. Additionally the elements could have code for <Product Number> and finally the location of the element should be available

• Code
• Product Number
• Location

The code must of course have a reference to a code that exists in the <Main Type Tree> in MainManager for this database.

Here is an example for <CCS Main Type Code>:

Preparation for the Import

First step in creating building systems from BIM model is to prepare the BIM elements for actual object creation. That action tests the BIM elements to see if they have a code that matches the classification system, and if so attaches the element to the type structure in MainManager. It also fetches Product number if that is demanded in the mapping set. Also it tries to find the location of each element in the location structure. Elements that do have an invalid code are marked as having an error. The user should then correct the model and reimport it.

What the user does here:

Run the action <Preprocess and validate BIM model system elements>

Purpose:

This action preprocesses the BIM elements that have been imported for a certain BIM model to check if they might actually be useful to create system objects and if they have a legal code. A mapping set that fits this model must exist that defines which attributes should be used for the system type and if there are other attributes that can be used for the objects. 

The system element preprocessing/validation action first gets all BIM elements belonging to the selected model and maps the attributes using the mapping set. Then each BIM element is processed in the following way going down the hierarchical structure of the IFC model:

1. Has the element a mapped value for the <Main Manager Type Code<?
   • If not, then the element is of no interest and the next element is processed
2. If the element has some type code then the code is processed (e.g. split into type part and product number part).
   • If product number is required and no product number found (either from code or mapping) then the element is marked as an error element with missing product number and the next element is processed.
3. The type code is then used to find the corresponding MainManager type (by looking at the existing main type tree). 
   • If it is only in one location in the hierarchical type structure a match is found and the element has a valid type code and get a corresponding MainManager type connection
   • If the type code (problem applies only to CCS type code) is located in more than one location in the hierarchical type structure then a search is done through the parent elements in order to find the exact type code. If that is successful the element has a valid type code and gets a corresponding MainManager type connection
   • If no or multiple Main Types are found for the given type code then the element is marked with and error (either no main type found or multiple main types found). For such elements it is possible to manually decide what is the right MainManager type code
4. If main type is found then the next step is to find the physical location of the system element. That is done by looking at the parent of the element and checking if that element is a location element. If the parent is a location element than that location is added to the system element being processed. If not that is continued until a location element is found or not.
5. Next step is to check if some quantity unit is provided by the element. If quantity unit is required and not found then the element is marked with error saying that quantity unit was not found.
6. Finally, the element is updated with all properties found (main type, product number and quantity) and the rest of mapped values (e.g. installation date, description, etc.).
7. This process is then repeated until all system elements have been processed

When all system elements have been processed then the system validation status of the BIM model is updated. The following statuses are possible:

• System validation passed: That means that no elements had errors.
• System validation passed with errors: That means that some (or all) of the processed elements had errors. The action returns a list of all the elements with errors with information about the type of error, the type code value and some other attributes of the element.
• System validation failed: That means that the mapping to main type code is missing for the selected mapping set.

When the system elements of the BIM model have been preprocessed and validated then it is possible to start connecting elements to product data and finally create the system structure from the elements.

Execution:

1. Press action <Preprocess and validate BIM model system elements>
2. Select the right mapping set for the processing
3. Run the action

The user can see how the mapping set attributes have been processed into the BIM elements by opening the registration window for a <BIM element>.

All attributes that were mapped (and had value) can be seen on each BIM element by clicking on the <BIM element attributes> sub-data tab.

Connect Product Number to Product Data (if imported with the elements) 

On the right side of this step there is an overview of all the <Product Data> that exists in this database (on the selected site). If it has been selected to process the system elements with a product number, then they can be seen in the tree on the left side. One or more product number from the model could belong to a <Product Data> on the right side so that some useful information on e.g. manufacturer, quantities and more are registered in one place but connected to many objects (that are about to be created in next step).

The user drags the product numbers from the left side over to a product data in the right tree. To create a new product data, the user can simply drag the product number over to the top node in the right tree, then a new one is created (with a number and  the name of the first BIM element with that product number).

If the user wants to use a <Product Data> that exists on another site, the user can open that Product Data and connect to the sites she wants. She can also decide to connect it to more than one Main type.

To describe the term Product number versus Product data (Product data number) and the reason for having those two terms, the following example is introduced.

In a building there are 100 windows of different sizes from the same manufacturer. Each window size has its own product number registered on the elements in the BIM model (124-129). All the window elements have the same <SfB Type Code>. When the model is processed the result is the following:

All these windows have the same operation information and should be operated and maintained in the same manner. We are therefore not interested to fill out separately product information for each window. Therefore we connect Product numbers 124-129 into one <Product Data Number>. The supplier is later demanded to deliver data for each Product Data Number.

Here we decide that the product data number 124 Window is used for all product numbers 124-129.

If there are some elements that have invalid coding they appear in the bottom of the left tree.

The user has two possibilities. Correct the BIM model and import it again (recommended) or use following action (by right clicking the error node):

Here the user can decide to that these 178 elements get a selected <Main type> in the action.

When user has decided on the handling of different product numbers and taken care of wrongly coded elements he is ready to go to the next step, to register the actual systems in MainManager.