1. Home
  2. Docs
  3. DETANGLE® Knowledge Base
  4. DETANGLE® Metrics
  5. Maintenance Effort

Maintenance Effort

Maintenance Effort is the System Effort spent on fixing bugs or (depending on the filter settings) on technical improvements to reduce technical debt.

Maintenance Effort % is a DETANGLE® Performance Indicator and measures the maintenance effort percentage of the System Effort.

What does an ideal percentage of Maintenance Effort look like? Two larger surveys reveal that:

  • Developers spend on average 30% of their time on maintenance [1].
  • Developers spend across industries and countries on average 40% of their time on unplanned work (including bug-fixing) due to technical debt [2].

Thus, there are no general rules. According to our experience and along these survey numbers, we recommend the following pragmatic approach:

  • Plan for 20% of the effort to be spent on maintenance (i.e. bug-fixing and technical debt reduction).
  • You need to worry in case of passing the threshold of 40% over more than two iterations. Especially when not managing to use the effort for reducing technical debt. Otherwise technical debt starts to accumulate and get unmanageable at all.

Therefore,  icons in the DETANGLE® diagrams on Maintenance Effort are used for the following two thresholds:

  • 👎 over 40% of the system effort has been spent on maintenance in the last time period.
  • ⚠️over 20% (but less than 40%) of the system effort have been spent as maintenance effort in the last time period.
  • 👍 less than 20% of system effort is spent on maintenance.

The Maintenance Effort % is calculated along the code structure of the code base, for files, folders, the whole system and for each time period:

Granularity/
KPIs or Effort Metrics
per 

bug

per

“functional” issue

per 

file

per

folder

per

entire

system

Maintenance

Effort (cLOC)

x x x x
Maintenance 

Effort %

x x x x
Maintenance Effort Ineffectiveness x x x x
Feature Effort (cLOC) x x x x
Feature

Effort %

x x x x
Feature

Effort Effectiveness %

x x x x
System Effort (cLOC) x x x

Take a look at DETANGLE® Metrics at a Glance for an overview of all metrics.

Links

[1] https://blog.tidelift.com/developers-spend-30-of-their-time-on-code-maintenance-our-latest-survey-results-part-3

[2] https://stripe.com/de/reports/developer-coefficient-2018: More than 1,000 developers and more than 1,000 C-level executives in the US, U.K., France, Germany and Singapore participated in the study

Was this article helpful to you? Yes No

How can we help?