Creating a cost item
Each cost Item contains information about the unit price of a task activity, information how it will be connected with model elements (Element Query) and information how the quantities will be extracted from BIM model elements (Quantity formula). The unit price can be expressed using resources; however, this is not a requirement. It is also possible to input a fixed unit price for the cost item. It also contains information about quantity type and measurement unit. Cost items correspond to the items in the list of works and can be linked to a model elements in two ways. The first method is to manually link the cost item to specific elements, while the second method entails defining the Element Query of the cost item, which represents set of rules. Based on the specified rules, the software will automatically identify elements that satisfy the designated criteria. It is crucial to note that the process of defining the query is similar to the process of defining criteria for smart selection sets. Rules for defining query expressions are clearly outlined in the excel file, which can be exported from the Cost Editor tab. The process of creating the Cost Item can be executed in four different ways, similar to the Classification Item creation process. By carefully following the instructions outlined below, the user can create high-quality Cost Items that meet their project requirements.
Creating cost items automatically based on predefined QTO (Quantity Take-off) or CBS (Custom Breakdown Structure) through the Creation Wizard
To basic Cost classification structure can be defined using QTO or CBS functionalities, both of which offer the ability to sort BIM elements based on any property on multiple levels, thereby enabling quick creation of a basic Cost classification structure. Using the Cost Creation Wizard, the basic Cost classification structure can be automatically generated, containing all Cost and Classification items defined based on previously generated QTO/CBS, and thereby streamlining the process. The following steps describe the process:
Activate the Cost Editor tab → Click New Classification within the Cost Editor.
New Classification → The New Classification window will open → In the Description field, give the name of the new classification → Finish the process by clicking OK.
New cost classification is active and automatically selected → Click Creation Wizard in the second toolbar line → Select From Quantity Takeoff or From Custom Breakdown option → The Creation Wizard window will open→ Choose desired, already predefined, Quantity Takeoff or Custom Breakdown structure from the drop-down list
Also, the Code of Cost items can be auto-generated from QTO/CBS, or can be defined using [Schema] through the previously explained Define Code command. The Cost Item Name can also be generated from QTO/CBS, From Knowledge Base or From Custom Template. The same options are available for Cost Item generation, with additional options for the Code based on the properties defined in each BIM model element. Furthermore, Rules of Measurement can be defined from available options such as: From Quantity Takeoff, From Knowledge Base and From Custom Template
→ Finish the process by clicking OK.
With this workflow the whole cost classification will be automatically generated with all Classification Items and Cost Items. For further adjustment of cost classification in terms of Unit Cost, Quantity Type, Quantity Unit and Quantity Formula, export the Cost Classification to Excel and make adjustments. After that, the table with all necessary data can be imported into the BEXEL Manager environment. Besides this workflow, mentioned data can be changed directly in BEXEL Manager. Using Creation Wizard and automated generation of Classification Items and Cost Items, Cost classification will have all defined Element Queries, which allows using the Auto Assign command and automatically assigning all Cost Items to proper BIM model elements.
At the end of the process, a complete Cost classification structure is defined, with classification and cost items created based on information from QTO or CBS. QTO/CBS structure definition parameters define element query and Cost item description. Automatically created Cost items and Classification items could be easily modified by exporting Cost classification in Excel or manually modifying Classification Items and Cost Items through the Edit command in the second toolbar line.
Typical Cost classification has different Quantity formulas for calculation (based on different rules of measurements), and also, cost items have different Unit cost (prices), based on various resources used or based on local market prices. By default, using Creation wizard to generate cost classification from QTO/CBS will initially place the same Cost Unit for all created Cost items. The only thing that requires manual editing is to specify Cost Unit for each cost item.
Cost item creation from a new definition
Creating Cost item From New Definition means creating a blank Cost item and defining all properties within Cost Item Editor:
Click on the classification item under which the new cost item will be placed → Click New in the second toolbar line and choose Cost Item from New Definition or use right click on the classification item under which the new classification item will be placed and choose New Cost Item and then choose From New Definition → Cost Item Editor window will open → Define Code, Name and Description of created Cost item and define Cost item parameters within three tabs General, Resources and Mappings → Within the General tab add information like Daily Output, Quantity Type and Quantity Unit.
While the Unit Cost is calculated based on other Cost Item costs (Material Supplement Cost, Labor Supplement Cost, Equipment Supplement Cost) → If it’s needed to change the Unit Cost, consider modifying the Other Cost or Subcontractor Cost fields → Within the Resources tab add information related to resources by clicking Add → The Resource Picker window will open → Pick the desired resource and define Quantity and Waste Factor at the bottom of the Resource Picker window → Finish the process by clicking OK → Within the Mappings tab, add the Query and Quantity Formula by clicking Change next to Query or Quantity Formula → The Element Query Editor window will open → Click Insert Query as explained in the Creating a classification item section → Finish the process by clicking OK → Finish the process of Cost Item creation by clicking OK.
All properties are set to zero or default values and must be defined by the user.
Editing the cost item
Select the Cost Item to change → Click Edit in the second toolbar line or right-click on the cost item and then choose Edit Cost Item → The Cost Item Editor window will open → Enter the desired changes → Finish the procedure by clicking OK.
There are two options when editing Cost Item: Edit Cost Item and Edit Cost Item Instance. The difference between them is that you can edit only the Code, Name and Description with the Edit Cost Item Instance. On the other hand, with Edit Cost Item, you can change other data.
Copying the cost item
Select the Cost Item to copy → By right-clicking, the window will activate → select Copy → Select a Classification Item to copy the map structure → By right-clicking on the selected place, a window will be opened → Choose Paste.
Cutting the cost item
Select the Cost Item to cut → By right-clicking, the window will activate → Select Cut → Select a Classification Item to paste the map structure → By right-clicking on the selected place, a window will be opened → Choose Paste.
Deleting the cost item
Select the Cost Item to delete → Click Delete in the second toolbar line or use right click on the classification item → Choose Delete → A notification will pop up asking if you really want to delete this item → Finish the procedure by clicking Yes.
Cost item creation from the existing definition
This option is very useful when creating a new Cost item similar in definition to some of the already created Cost items (This is often the case on the project). The process is similar to above mentioned:
Click on the classification item under which the new cost item will be placed → Click New in the second toolbar line and choose Cost Item from Existing Definition or use right click on the classification item under which the new classification item will be placed and choose New Cost Item and then choose From Existing Definition → The Cost Item Definition Picker window will open → Find existing Cost item you want to base your new Cost item on and click OK (user can find any Cost item in the project regardless of actual cost classification) → A copy of existing Cost Item can be edited by right-clicking on newly created Cost item → Select Edit Cost Item Definition Editor and edit Code, Name and Description of the new Cost item as well as information that differs from the initially copied Cost item.
New cost item created from the existing cost definition is working as a reference. It will have the same values as the original cost item upon which is based and changing any of the cost parameters will also affect the original cost item. Also, changing values in the original cost item will change values in all cost items created based on it. Note that you can’t create new cost item from the existing in the same classification item, these cost items have to be in different classification items.
Cost item creation in Excel file
To create a new Cost Item in an Excel spreadsheet, insert a new row below the Classification item under which the new Cost item will be placed in the structure and define the following properties.
The Outline level should be the same as the outline level of the Classification item in which your Cost item is placed, and just add .0 at the end of the string (For example, to add a Cost item within Classification item 22.214.171.124, the outline level of Cost item will be 126.96.36.199.0). So all Cost items within one Classification item have the same outline level; there is no need for hierarchical leveling of cost items in the way that’s required for Classification items.
All other fields, except Element Query and Quantity Formula, are defined by a user depending on information from the cost database used on the project. All fields must be formatted according to the rules specified in the Help sheet.
Element Query is defined in a similar way it was done for the Classification item. It could be based on Category, Family name, Material Name, or having or not certain property or a specific value of the certain property. It could also be a combination of any of the before mentioned as Any of the following conditions or All of the following conditions and negation of expression with Negate command, which could be significant in certain project conditions. Exact rules for expressions that could be defined in Element Query should work in a similar way as the rules for defining smart selection sets, and these expressions for creating rules are explained in the Help sheet of Excel file.
The Quantity Formula field represents the mathematical formula defined to calculate quantity for that specific Cost item. To count the number of elements, the quantity formula is simply 1. However, the quantity formula could also include any numeric property the model element has (area, volume, length, etc.). It could also be used to define more advanced calculation formula (For example, to calculate the area of formwork needed for a concrete beam element, you can calculate it in this way (2*h +b) *[Length] where h, b (beam width and beam height) and [Length] are numeric properties of model elements).
Only numeric element properties could be part of the Quantity formula. Text properties could only be used in Element Query. It is important to properly format all properties added in authoring tools as numeric if you want to use it for calculation in the Quantity formula.
In the latest BEXEL Manager version, for more advanced use cases it’s possible to use some textual properties within the Quantity formula but only when using the logical function IF. In that case, the textual property will differentiate what numerical properties or formulas that shall be used based on textual property value.
Additional properties could be added through an inbuilt console API scripting tool.