In some instances, the metaphorical principal (MPrin) of a technical debt is a missing or incompletely implemented capability. For example, absence of a fully automated regression test suite can create difficulties for testing a complex system. Defects can slip through. That would result in reduced productivity and velocity. In this case, the projected cost of implementing, testing, and documenting the test suite, and training its users, would constitute the initial MPrin of the outstanding technical debt. This definition differs from some definitions, because it includes testing, documenting, and initial training. In general, from the enterprise perspective, when identifying the MPrin associated with missing or incompletely implemented capabilities, we must include all artifacts necessary to eliminate reductions in productivity and velocity.
But even if we include these items in the conventional definition, MPrin at retirement can exceed the savings at the time we incurred the debt. For example, in the interval between origination and retirement the assets involved can change. Moreover, if retiring the debt causes a revenue stream interruption, the MPrin, which includes the lost revenue, can be significantly larger than the initial MPrin.
Unique problems of incompletely implemented capability
A concrete building under construction. Concrete takes about a month to cure and reach full strength. If we waited for full curing before pouring the floor above, multistory concrete construction would be slow and expensive. So we start on the next floor after only a few days. Because the floors can’t support themselves for about a week, we shore them using lower floors. The shoring constitutes a technical debt resulting from the “incomplete implementation” (partial cure) of each floor. We retire that debt by removing the shoring as we go. More about shoring and re-shoringTechnical debt associated with incompletely implemented capability presents unique problems. We can retire it in three distinct ways. First, we can complete the implementation. The MPrin associated with this approach can grow beyond the initial cost of completion, for the usual reasons. Second, we can cancel the capability. If we do, retiring the debt completely would require removal of all artifacts that we no longer need. Finally, we can choose a middle path. In the middle path we adopt some parts that have been completed. But we reject other parts, and we add whatever is necessary to create a limited version of what we originally planned.
Special challenges of non-physical assets
Invisibility is an important attribute of non-physical assets such as software, procedures, legislation, regulations, and so on. Technical debt associated with incomplete implementation is difficult to manage in such assets. For example, the image above shows several levels of a concrete building under construction. The vertical members between the levels are part of a shoring system that supports the levels of the building. Shoring is necessary until the concrete floors cure well enough to support themselves. Shoring constitutes a kind of technical debt that must be “retired” before the building is complete. The teams constructing the building could never forget to remove the shoring because it obstructs installation of the windows and walls.
But things are very different with non-physical assets. It’s easy to forget to remove intermediate artifacts, or elements that were part of attempts that didn’t work out. Many non-physical assets are perfectly functional carrying that kind of technical debt. That debt becomes evident with time, as the asset becomes increasingly difficult to maintain, extend, or defend.
It’s this property of non-physical assets that makes technical debt management so much more difficult than it is with physical assets. Not more important, just more difficult.
The Metaphorical Principal of a technical debt that’s incurred as a result of a change in standards or regulations, internal or external, is the cost of bringing all affected assets into full compliance. Properly accounted for, however, the MPrin should include ripple effects, which are the changes in other assets that are required to keep them compatible with the assets that are directly affected.
Platform component upgrades often trigger the need to make changes in whatever sits atop the platform, to maintain compatibility with the platform. Those changes obviously contribute to MPrin. But less obvious are the contributions that arise from deferring the upgrade.
The MPrin of an asset that is subjected to new development or enhancement has some special characteristics. For an existing asset, new development can lead to duplication of capability. For new assets, unanticipated opportunities can transform into technical debt components that were not viewed as technical debt, without ever changing them in any way.
Some examples might help to clarify the differences between the principal of financial debts and the Metaphorical Principal of a technical debt. The examples to come in the next four posts are designed to illustrate the unique properties of MPrins of technical debts.
Expect the unexpected with technical debt retirement efforts, because they can conflict with ongoing operations, maintenance of existing capabilities, development of new capabilities, cyberdefense, or other technical debt retirement efforts. Policymakers can make important contributions to the enterprise mission if they can devise guidelines and frameworks for resolving these conflicts as closely as possible to the technical level.
The principal amount of a financial debt and the metaphorical principal of a technical debt have very different properties. They are so different that it’s wise to avoid using the term “principal” to refer to the metaphorical principal of a technical debt. We use the term MPrin.
