Last updated on July 12th, 2021 at 03:05 am
The MPrin of technical debt that forms as a consequence of a platform component upgrade depends on how we incur the debt. If we incur the debt by installing the upgrade, and then perform only some of the work made necessary by the upgrade, then the MPrin is the total cost of performing the deferred work. If we incur the debt by deferring the upgrade, then the conventional definition of the MPrin has two components. The first is the cost of the upgrade, and the second is the cost of any work made necessary by the upgrade, but not performed.
Hold on—it’s not so simple
In this latter instance, MPrin can increase over time. Increases can occur if the following three-step sequence happens for either maintenance or enhancements. In step 1, we perform work in the environment of the obsolete platform component, but after deferring the upgrade. Step 2 is performance of the upgrade. In step 3, we must repeat the work we performed in step 1 because the step 1 version isn’t compatible with the upgrade. This situation can be even worse if we discover the need for step 3 as a result of operational failure after the upgrade. In that case, maintainers must investigate the failure first. And the failure might cause database contamination, which would also need remedying. These additional costs are actually part of the debt retirement effort for the debt incurred by deferring the upgrade, but we usually account for them—mistakenly—as routine operational expense.
Advance knowledge of what can go wrong is always a nice-to-have. Most of us try to acquire this knowledge before or as we plan our projects. And most of us can do better. Before you consider a plan complete, ask yourself if anyone else might have already tried something similar. If you can guess who that might be, contact him or her to find out how it went. No point repeating someone else’s mistakes.
[Boss 2011] Richard W. Boss, “RFID Technology for Libraries,” American Library Association, 2011.
Some libraries are upgrading their book tagging systems from barcodes to RFID tags—what is essentially a platform upgrade. When they do convert, every item in their collections becomes an instance of technical debt until it’s tagged with an RFID. A tagging technician can process about 1,000 items per day. It’s a big job. Available: here; Retrieved: November 21, 2017