Abstract
Context: Fulfilling non-functional requirements (NFRs) is essential for the success of software systems. Nevertheless, NFRs are often treated second class when compared to functional requirements in development projects.
Objective: To better understand the nature and effects of this imbalance, we explore the under-documentation of NFRs as an Indicator of Technical Debt.
Method: To achieve our aim, we exploit responses from an independently sourced global survey on requirements engineering: NaPiRE 2018. We analyze the responses under the assumption that NFRs related to quality attributes considered important must be documented. First, we retrieve data about the degree of documentation of NFRs and the perceived importance of quality attributes as defined by the standard ISO25010. Then, we check whether NFRs related to important quality attributes are reported as documented. If they are not, we consider this to be an indication of Technical Debt. Results from the statistical analysis are compared to findings from the literature.
Results: Our first finding is that there is no uniform pattern of what respondents consider to be important or unimportant quality attributes. However, the majority of respondents indicated that NFRs related to Maintainability, Reliability, Usability, and Performance were considered important.
While the majority of responses confirm our expectation that NFRs related to quality attributes considered important are documented and NFRs related to quality attributes considered unimportant are not, there are responses indicating that NFRs related to important quality attributes are actually not documented. According to our assumption, these responses point to the existence of Technical Debt.
As a side-product of our analysis, we also noted the existence of NFRs considered unimportant and documented.
Conclusions: The presence of Technical Debt in NFR documentation may create different types of problems with several unwanted consequences, such as dissatisfied customers and inefficient development. Assuming that Technical Debt correlates with insufficiently documented NFRs of important quality attributes, we conclude that more effort should be spent by development organisations on adequate documentation of NFRs. It will pay off.
Objective: To better understand the nature and effects of this imbalance, we explore the under-documentation of NFRs as an Indicator of Technical Debt.
Method: To achieve our aim, we exploit responses from an independently sourced global survey on requirements engineering: NaPiRE 2018. We analyze the responses under the assumption that NFRs related to quality attributes considered important must be documented. First, we retrieve data about the degree of documentation of NFRs and the perceived importance of quality attributes as defined by the standard ISO25010. Then, we check whether NFRs related to important quality attributes are reported as documented. If they are not, we consider this to be an indication of Technical Debt. Results from the statistical analysis are compared to findings from the literature.
Results: Our first finding is that there is no uniform pattern of what respondents consider to be important or unimportant quality attributes. However, the majority of respondents indicated that NFRs related to Maintainability, Reliability, Usability, and Performance were considered important.
While the majority of responses confirm our expectation that NFRs related to quality attributes considered important are documented and NFRs related to quality attributes considered unimportant are not, there are responses indicating that NFRs related to important quality attributes are actually not documented. According to our assumption, these responses point to the existence of Technical Debt.
As a side-product of our analysis, we also noted the existence of NFRs considered unimportant and documented.
Conclusions: The presence of Technical Debt in NFR documentation may create different types of problems with several unwanted consequences, such as dissatisfied customers and inefficient development. Assuming that Technical Debt correlates with insufficiently documented NFRs of important quality attributes, we conclude that more effort should be spent by development organisations on adequate documentation of NFRs. It will pay off.
| Original language | English |
|---|---|
| Article number | 28 |
| Journal | Software Quality Journal |
| Volume | 33 |
| Publication status | Published - 30 Jun 2025 |
Keywords
- quality characteristics
- quality attribute
- non-functional requirement
- technical debt