Automated Unit Testing (using Tessy Tool) for a Body Control Module (BCM) Application

About the Customer:

This is a success story of one of our highly value-add partnership with a Tier-1 supplier of Automotive components.

While working on one of their ambitious projects related to Body Control Module, our customer felt the need for technology assistance related to automated unit testing of certain components.

Business Challenge:

In order to prove the competency of the products to the OEMs, the customer was required to provide unit testing reports of the software components such as in-vehicle communication (CAN, LIN), low-level drivers and vehicle diagnostics stacks (UDS stack).

In the absence of in-house skills related to Automation in Software Testing, the customer faced headwinds in showcasing the required testing reports to the OEMs.

Our customer had earlier collaborated with our automotive software team for the development of low-level drivers and implementation of our ready-to-deploy production-grade protocol stacks such as CAN BUS, UDS, OBD etc.

So, it made sense for them to take us on-board for the unit testing project as well.

Moreover, our software testing team already had an in-depth expertise in the Tessy Unit Testing Tool, which made us a preferred technology partner for our customer.

Embitel’s Solution:

Leveraging our expertise in Automated Unit Testing, using Tessy Tool, we started the process with one component at a time. Hence, we kick-started the unit testing project starting with Low-level device drivers and proceeding to protocol stacks.

Here is the snapshot of the workflow of our automated Unit Testing:

• We designed the test cases, using Classification Tree Editor (CTE), based on the requirements provided by the customer.
• Test data including the input variables and expected output values was determined.
• Test result was evaluated and visualized with the help of different color codes.
• Code coverages like Statement Coverage, Branch Coverage and MCDC were analyzed.
• Test Report was then generated, as per the required template.

Test Result AnalysisThe following Software modules were tested using Tessy (Unit Testing Tool):

1. CAN BUS Drivers.
2. UDS Protocol Stack (ISO 13400).
3. Low-Level Drivers such as NVM, Timer, SPI, ADC, MCU,Clock.
4. Base Software Module (BSW) including NVM Handler, PWM Handler, Scheduler and more.

Embitel Impact:

Due to our extensive experience in Automation Tool (Tessy Tool for Unit Testing), our team was successful in delivering all the value-adds of Automation of Unit Testing Process.

Compared to manual unit testing that takes close to 8 man hours per module, we were able to complete unit testing of one module in 2 man-hours.

Other value-add was the enhanced accuracy, due to lesser degree of human intervention in various stages of Unit Testing.

Tools and Technologies:

Tessy Test System from Razorcat: The Tessy Tool automates the unit test life-cycle for testing of the embedded software and systems. From test creation to unit test report generation, Tessy Tool makes is an end-to-end testing automation environment.

Different Types of Reports that can be generated using Tessy Tool:

• Test Details report
• Test Overview report
• Planning coverage report
• Execution coverage report