SCALAR Brake performance overview #
The SCALAR Brake performance module collects detailed data on braking events from the electronic braking system of a trailer. This data helps assess the overall health and performance of the brakes, facilitates maintenance, and reduces the need for regular physical roller brake tests.
The SCALAR Brake performance module generates brake performance metrics that provide vital inputs to trailer owners and operators about when maintenance would be beneficial.
- In the UK, the Driver and Vehicle Standards Agency (DVSA) allows trailer owners or operators using a Brake Performance monitoring system, such as SCALAR Brake performance, to reduce the need for physical testing from quarterly to annual basis, offering a significant operational benefit.
- This functionality is subject to user permissions. Only a Dispatcher and the Brake Performance Manager can access the Brake performance app.
Mechanism: The SCALAR Brake performance app collects data from the trailer’s Electronic Braking System for individual braking events (captured every 10 milliseconds while pressure is applied to the brake pedal), processes the data based on an algorithm, and computes a daily brake performance value (BPV) for each trailer. The BPV is then compared to a DVSA-specified criterion to determine whether the trailer passes, fails, or warrants action.
Brake performance calculation #
The Brake performance app is used to measure and report the brake performance daily values, visualize performance trends over time, record testing events and results, maintenance events and comments, and generate compliance reports for regulatory review or submission.
The daily BPV is measured in units of % gravity (denoted as g), which is a % of 9.8 meters per second squared (m/s²). This represents the acceleration due to gravity on Earth’s surface.
45% g is the passing value for most trailer types, but the BPV value recorded for drawbar and center axle trailers must be at least 50% g.
Using 45% g as the pass rate, a deceleration of 4.41 m/s² at a brake pressure of 6.5 bar is required.
This implies that to pass the test, at a brake pressure of 6.5 bar, the trailer must decelerate from 100 km/hour to 0 km/hour in 6.5 seconds.
To generate the braking events required to compute brake performance, individual trailers or devices must be activated through an API.
View Brake performance dashboard #
From the Brake performance dashboard page, you can track the latest BPV for each trailer, view the status, and the action taken for those trailers whose BPV falls short of the criterion set by DVSA.
In the Home module, from the left navigation pane > click Brake performance 
. The Brake performance dashboard page is displayed.
Click Sort 
in the column headers to sort records in ascending or descending order.
The option to record or edit interventions, comments, and/or service window is available only to the Brake performance manager.
Available columns
Field |
Description |
Name |
Name of the asset NOTE:
If this field is not filled in, the license plate is used as asset name. |
License plate |
Unique vehicle registration number used for identification and vehicle management |
Data consumer |
Names of organizations that are consuming the trailer data through data sharing agreements—this field will be blank if the trailer is not currently shared |
Braking value |
Predicted BPV expressed as %/g at 6.5 bar based on the valid brake events during the relevant service window which is between 4 and 13 weeks Records the last known brake performance status Action required: The braking performance value does not meet the standard based on the pressure at 7.5 bar. Action is required. Low performance: The braking performance value meets the standard based on the pressure at 7.5 bar. Pass: The braking performance value meets the standard based on the pressure at 6.5 bar. Unqualified: Not enough braking events have occurred to calculate a valid braking performance value within the required margin of error. Gathering data: In the initial 30-day period, insufficient braking events have occurred to calculate a valid braking performance value. Additional braking data is needed. NOTE:
The braking performance status is calculated daily using all valid braking events within the service window. This rolling calculation typically results in status changes as new braking events are added and older ones expire. The standard is 45% for most trailers, but 50% for center-axle and drawbar trailers. |
BPV 7.5 |
Predicted brake performance value expressed as %/g at 7.5 bar based on the valid brake events during the relevant service window that is between 4 and 13 weeks. This is used to determine if a non-passing trailer is having low performance or action is required |
Braking status |
The last known braking performance status Action required: The braking performance value does not meet the standard based on the pressure at 7.5 bar. Action is required. Low performance: The braking performance value meets the standard based on the pressure at 7.5 bar. Pass: The braking performance value meets the standard based on the pressure at 6.5 bar. Unqualified: Not enough braking events have occurred to calculate a valid braking performance value within the required margin of error. Gathering data: In the initial 30-day period, insufficient braking events have occurred to calculate a valid braking performance value. Additional braking data is needed. NOTE:
The braking performance status is calculated daily using all valid braking events within the service window. This rolling calculation typically results in status changes as new braking events are added and older ones expire. The standard is 45% for most trailers, but 50% for center-axle and drawbar trailers. |
Intervention |
The last intervention status and comments as described below:
|
Mileage |
Total distance traveled by a trailer that is recorded by the vehicle odometer |
VIN |
Unique vehicle identification number of a vehicle |
Comments |
The most recent comment added by a brake performance manager |
Days in action required |
Number of continuous days that the trailer has had a BPV status of ‘Action required’ |
Days in low performance |
Number of continuous days that the trailer has had a status of low performance |
Days since last intervention |
Number of days since the last intervention was taken |
Last intervention mileage |
Mileage recorded during the last intervention |
IMEI |
The serial number of the telematics communication unit mounted on the trailer, which transmits the brake event data from the electronic braking system |
Valid brake events |
The number of valid brake events during the specified service window for this trailer, which is used in the calculation and presentation of the BPV and status |
Last brake event |
The date and time stamp of the most recent brake event registered by this trailer used in determining the brake performance |
Service window |
Represents the optimum frequency of service based on trailer age and use It is used in the calculation of the BPV, and it can only be changed by a Brake performance manager |
Company owned |
Indicates whether your organization owns this asset and will be allowed to record brake performance management activities on it such as interventions, service window changes, and comments. NOTE:
Non-owners (data-sharing consumers) will be able to view, but not add or edit this data. |
Code |
An identifier available to an organization NOTE:
The code is often used by organizations who subcontract their trailers to other organizations. |
Last valid status and date |
If the braking performance status is Unqualified, it is most likely because there are not enough braking events in the service window to meet the margin of error requirement. It is likely that in the past, a valid status was generated since the duration is a rolling window. If the current status is ‘Unqualified’ and a prior valid status exists, that status and the date are displayed together in this column |
Fleet ID |
An identifier available to an organization |
TBS Brand |
Trailer braking system brand |
TBS Model |
Trailer braking system model |
Filter records #
You can filter records to narrow search results based on the brake performance status and interventions.
- To open the filter panel, on the Brake performance page > click Filters. The Filter pane is displayed containing the following options: Braking status, Intervention, Notifications (active or inactive), and TBS Brand.
- In each section, select the required checkboxes, and then click Done. The records that fulfill the criteria are listed. This table contains the description of the checkboxes in the Intervention section.
You can also filter the records based on the brake performance status by clicking the tiles on the Brake Performance dashboard page. 
Selection |
Description |
Laden RBT – Fail |
The trailer’s braking system has had a laden Roller Brake Test (RBT) and the result is “fail”. Action is required. |
Laden RBT – Pass |
The trailer’s braking system has had a laden Roller Brake Test (RBT) and the result is “pass”. No action IS required. |
Relined |
The trailer’s braking system has had a reline. |
Other |
Intervention taken besides those specified earlier |
Export brake performance records #
The brake performance records can be exported as a CSV file for analysis and reporting from the Brake performance page.
In the Home module, from the left navigation pane > click Brake performance 
. The Brake performance page is displayed. Click Download csv.
The exported data is downloaded as a CSV file to the Downloads folder on your computer.
The image below shows a sample CSV file downloaded containing Brake performance details.
Notifications #
Notifications are generated when a trailer’s brake performance status is ‘Low Performance’ or ‘Action Required’ for the first time, then again if the status remains unchanged after 7 days, and once again after 14 days. For more information, see Notifications.
In-app and email notifications are enabled for all users by default, though they can disable email notifications. This is a sample image that shows the Notifications pane for assets where the brake performance is low or where action is required.
When signed in, you can view and configure notifications on the Notifications pane in the upper-right corner in the header, irrespective of the module you are currently in. 
Search brake performance records for a trailer #
On the Brake performance dashboard page, you can search specific records by using the Search feature based on the asset name, license plate number, or data consumer. In the Search by name, license or Consumer box, enter the required asset name, license plate number, or data consumer, and then click the Search icon (
). The records matching the search criteria are listed.
Brake performance visualization #
By using the Brake performance app, you can view the graphical representation of the brake performance for each trailer. Suitable measures or action can be initiated for those trailers where the BPV falls short of the criterion.
On the Brake performance dashboard page, click the required trailer. The page containing various graphs is displayed as separate segments explained in the following section.
The BPV is calculated daily using all valid (not filtered out) braking events during the configured service window, which varies from 4 to 13 weeks. Most newer trailers under normal use will use 13 weeks (91 days) as the service window.
1. Trailer performance: Depicts the trailer performance during the service window.
2. Brake events: Depicts the number of braking events per day during the service window.
3. Average deceleration and average pressure: Depicts the average deceleration and average pressure of each of the braking events during the service window used in the BPV calculation.
The blue line is extrapolated to the 6.5 bar (a unit of pressure) orange line and the 7.5 bar gray line. The intersection of the orange lines represent the passing values (45% g at 6.5 bar for most trailers). The extrapolated pressure at 7.5 bar is used to differentiate between ‘low performance’ and ‘action required’ for trailers that don’t meet the 6.5 bar pressure.
Interpretation: In this example, the blue (actual) line is above the intersection of the horizontal and vertical orange (qualifying) lines at 6.5 bar. Therefore, the brake performance of the trailer is considered to have passed, with a BPV of 80% as in June, 2025.
This image represents brake performance status that is unqualified due to insufficient braking events to calculate a valid BPV satisfying the required margin of error. 
- Most trailers need to exceed the 45% g value. Drawbar and center axle trailers must exceed 50% g.
- 13 weeks work out to 91 days.
Initiate action for trailers #
The dispatcher can identify trailers for which the BPV falls short of the criterion—the value is below the standard and thereby initiate action to address the issue. This ensures vehicle safety and compliance to regulations.
During the normal course of operations, a dispatcher or Brake performance manager can undertake remedial measures or actions to address low performance—they can follow up with the workshop, mechanic, or driver.
- On the Brake performance dashboard page, click the Action required tile. The trailers for which the BP status is ‘Action required’ are listed.
- Click the required record to visualize and analyze its brake performance over the service period.
After identifying the trailers whose braking status is sub-optimal, the required interventions can be initiated, such as repair and maintenance, brake component replacements, brake lining, brake system upgrades, or seeking professional assistance.
Only a Brake performance manager can initiate actions to address low performance. For more information, see the next section.
Brake performance management actions #
In response to braking statuses of low performance or action required, the trailer owner or operator must take follow-up actions, which may include visual inspections, brake cleaning or adjustment, relining, and conducting a roller brake test.
The actions taken must be noted in the Brake performance module by a user who is assigned the Brake performance manager role—either as comments, or interventions, or both.
The Brake performance manager can also change the service window for a trailer, which is set at 13 weeks initially. The appropriate service window for a trailer is a function of the age and usage patterns of each trailer.
Changes to the service window will be reflected in the next daily calculation, and they determine the span of time that braking events use in the calculation. For example, for 13 weeks, all braking events from the last 13 weeks are evaluated for usage to calculate today’s braking status. If a 4 week service window is used, it is deduced that servicing is needed every four weeks because of the conditions of use, and braking events from only the last four weeks are used while calculating today’s braking status.
- The Brake performance manager must add an intervention if either the brakes are relined, a roller brake test is performed, or any other intervention is resorted to.
- Comments can also be added at any time to capture other actions that might be taken, such as visual inspections or cleaning, or they can be added when an intervention is taken.
- The service window represents the optimum frequency of service based on trailer age and use and ranges between 4 and 13 weeks.
While entering brake performance management actions, you can initiate one or more of these actions: enter the intervention and details, add a comment, and/or change the service window: they are all independent actions.
- On the Brake performance page, click the Add or Edit
icon next to the trailer record to initiate interventions, add or edit comments, and change the service window as shown in this image. 
A dialog opens for you to enter the intervention details on the Intervention and comment tab.
- Enter information in the various sections as described in this table.
- None (default option in case of no intervention being taken)
- Laden Roller Brake Test (RBT) results (the Pass and Fail options are enabled)
- Relined
- Other
- Click Save. The information is saved and an acknowledgment message is displayed.
- Click the link provided in the Saved dialog to view the History tab, which tracks the asset management history. You are directed to the History tab.
icon next to the trailer record to initiate interventions, add or edit comments, and change the service window as shown in this image. 
Intervention: Enter information of the last intervention carried out and the result |
|
Intervention type options |
Select an option to indicate the intervention type: |
Date |
Enter the date when the intervention was carried out |
Mileage |
Enter the mileage recorded at the time of the intervention |
Service window |
Use the slider to specify the service window period A change in value will be reflected from the next daily calculation onwards. |
Comments |
Enter information that can serve as additional inputs or reference |
Generate Brake performance report #
The brake performance report contains the BPV and status of the selected trailer in compliance with regulatory requirements stipulated by UK or equivalent authorities.
Each report represents the BPV status for a single trailer on a specified date. However, the result on that date is based on brake events from the configured service window, which can be between 4-13 weeks.
You can generate the Brake performance report for a single (explained in this section) or for muliple assets.
- On the Brake performance page, click the required trailer record to go to the trailer information page. The brake performance for the selected trailer is charted in the following sections during the service window: Trailer performance, Brake events, and Average deceleration and pressure.
- Click Generate reports, which is located on the top right corner of the page. The Once-off Brake Performance report page is displayed.
- Enter information in the various sections as explained in this table.
- Select One time to generate a one-time report for an earlier date.
- Select Schedule to specify the reporting period and define the frequency to generate the report through email.
- Click Create Brake Performance report.
The brake performance report is generated and emailed to the specified recipient email addresses. You are directed to the One-time reports page.
Field |
Action |
What is the report about |
|
Report duration |
Select an option: One time or Schedule NOTE:
|
Report options |
In the Report name box, enter a name for the report |
Select assets |
Click Continue. NOTE:
No selection is required: the report will be generated for the selected trailer. |
Time period NOTE:
The explanation in this table is specific to a one-time report. For more information about how to generate a scheduled report, see Schedule a report and set the email frequency. |
|
Reporting period |
From the Time period list, select ‘Yesterday’ or ‘Custom’ |
Add e-mail recipient |
Select the Add e-mail recipient checkbox. The email-related fields are made available. Enter the recipient email address, subject line, and compose the email message. |
Click Export to download a copy of the report to the Downloads folder.
Schedule a brake performance report and set email frequency #
While building a brake performance report, you can specify the frequency and schedule for report generation on the Once-off Brake Performance Report page.
- On the Brake performance page, next to Report duration, select Schedule. The Schedule Brake Performance report page is displayed on which you can define the email frequency and schedule.
This image shows the relevant sections to define the email frequency and reporting schedule.
- Enter information in the E-mail frequency and Reporting schedule sections as explained in this table.
Section |
Action |
E-mail frequency |
Select the frequency at which the report will be emailed to the specified recipient: daily, weekly, or monthly. Select Daily to email the daily report generated. Select Weekly, then select the day the report will be emailed each week. |
Reporting schedule |
From the Start date and End date calendar pickers, select the date range for which the report must be generated |
You can also generate the performance report from Reports > Brake performance.
Click the Create Brake Performance report. The report will be generated on the scheduled date and emailed to the specified recipients. The report will also be listed on the Scheduled reports page (Reports > View Scheduled).
Generate report for multiple assets
On the Brake performance page, the Brake performance report can be generated for multiple assets.
- On the Brake performance page, click Reports, which is located on the top right corner of the window.
The Once-off Brake Performance Report page is displayed. - In the Select assets section, select the checkboxes next to the required assets (trailers), and then click Continue.
- In the Reporting period section, from the Time period list, select the required option: Yesterday or Custom.
- Select the Add e-mail recipient checkbox. The email-related fields are displayed.
- Enter the recipient’s email address (multiple email addresses can be entered), the subject line, and compose the email message.
- Click Create Brake Performance report. The brake performance report is created for the selected assets and emailed to the specified recipients. For more information about each section, see step 3 in the Generate Brake performance report section.
