Back on September 12th I posted a list of five rules for building test systems. Here's a few more...
Leave something for Phase 2.
You must resist the temptation to add new features to the system. Release the test system to production, and THEN work on your plans for the upgrade.
Do NOT hard-code specs. The specs will always change. Put the specs into a database that you can query, a spreadsheet file, or at least some sort of configuration file.
Log what happens. Make sure the software logs what happens - you cannot always rely on the technician running the test to write down what happened when and why.
Be aware of the environment.
Your test equipment or the DUT itself may change as the temperature, humidity or pressure change. You have to take this into account.
Know your accuracy.
You need to know the specs of the test equipment in your system. To be more specific, you need to know the specs for how you use the equipment, because vendors will sometimes list different specs for different conditions.