I was brought in to test a system that should have been ready. It wasn’t.

Multiple wiring errors. Installation faults that should have been caught before handover to test and commissioning. I knew the functional behavior of the system, what it was supposed to do, but I didn’t know the schematic details.

So I fault found it. On a program with tight deadlines and test tracks booked, on equipment I hadn’t been briefed on at the drawing level, under pressure to report daily progress to a project team that wanted percentages. This is a good way to learn a new system, but not a good way to fix things fast.

This got me thinking about maintenance tasks where faults and trains out of action can have serious cost implications. Being unable to provide full service can hit train and freight operating companies hard.

From this, Tracer was born and has now evolved from a maintenance tool to a maintenance and commissioning tool for safety-critical systems.

The record problem
Railway testing and commissioning is meticulous work. Every test has a procedure. Every result must be recorded. Every failure must be logged, investigated, resolved, and documented before the system is signed off. The audit trail is what proves the work was done correctly, not the engineer’s recollection.
In practice, that audit trail is often a ring binder, a spreadsheet updated at the end of the day, and whatever the engineer on shift can remember clearly enough to write down after ten hours on the tools.

“End of a commissioning shift: there are test certificates to fill in, test logs to record issues found, a site report to compile, and a project manager asking what percentage complete the program is. All of it was done manually. All of it was done from memory or notes taken during the day. All of it carries the human error that comes in when the person doing it is tired, and the information is already hours old.”

This is not a criticism of the engineers doing it (I am one of them). It is a description of the tooling available to them. Nobody has built something better, because the people who understand the problem well enough to build the right tool are the ones on the vehicles, not writing software.
I’ve spent many years in railway signalling – ETCS, CBTC, relay-based systems across major programs in London and elsewhere. I’ve written those end-of-shift reports. I’ve been in the update meetings to pass progress up the chain. I’ve been the engineer redoing testing or fault finding that’s already been completed, but was missed at handover.

At some point, I stopped accepting that this was just how it worked.

What Tracer does
Tracer is a real-time test record tool for safety-critical commissioning. It has two modules. Tracer Maintain is a fault-finding tool built to assist maintenance technicians and record fault-finding outcomes and progress. Tracer Test digitalizes test records and processes, and reports live progress to project teams.

Fault diagnosis module
Guided fault finding for relay circuits. The engineer loads the relevant circuit – ETCS, CBTC, relay-based, and works through a step-by-step procedure on their phone or tablet. Each step shows the instruction, the measurement point, the expected result, and highlights the relevant part of the circuit diagram. Tap any component to start fault-finding from that point. Navigate bidirectionally between relays and contacts without losing your place.