Economics-driven Technical Debt Management

Technical debt is a metaphor, stemming from economics, that resembles the delivery of software at poor quality to getting a loan. On the one hand, the costs saved during development boost the liquidity of the company (in the form of principal); whereas on the other hand, the poor quality produces additional costs (in the form of interest) along maintenance. This PhD project focuses on the financial nature of TD, and attempts to bring knowledge from the mature field of economics into the TD community. In particular, as a first step the project delivered the first systematic literature review, focusing on the economics nature of TD—providing a financial glossary and a taxonomy of the employed financial methods. Next, we assessed the industrial perception of TD, gaining insights on the need to explore the sustainability of TD in the future, considering various parameters. On top of these exploratory contributions, the main innovation offer by the project is two-fold. First, we delivered a novel interest theory based on the Liquidity Preference theory, named FITTED, which we instantiated at the source code TD level. FITTED considers the structural quality distance of the artifact under assessment from a (hypothetical) optimal one, as well as the historical evolution of the artifact. The TD interest assessment has been successfully validated in an industrial setting; and has been validated as related to TD principal, which strengthens the financial cornerstone of the metaphor suggesting that interest is calculated as a fraction of the principal. Finally, we provided an approach for treating architectural decisions (that are related to TD) as a financial investment. The corresponding approach (namely: ADMIT) relies on the cost-benefit analysis, giving the ability to consider both technical (such as complexity) and financial parameters (such as market share). ADMIT has also been successfully validated in industry

Architectural decision-making as a financial investment:An industrial case study

Context Making architectural decisions is a crucial task but also very difficult, considering the scope of the decisions and their impact on quality attributes. To make matters worse, architectural decisions need to combine both technical and business factors, which are very dissimilar by nature. Objectives We provide a cost-benefit approach and supporting tooling that treats architectural decisions as financial investments by: (a) combining both technical and business factors; and (b) transforming the involved factors into currency, allowing their uniform aggregation. Apart from illustrating the method, we validate both the proposed approach and the tool, in terms of fitness for purpose, usability, and potential limitations. Method To validate the approach, we have performed a case study in a software development company, in the domain of low-energy embedded systems. We employed triangulation in the data collection phase of the case study, by performing interviews, focus groups, an observational session, and questionnaires. Results The results of the study suggested that the proposed approach: (a) provides a structured process for systematizing decision-making; (b) enables the involvement of multiple stakeholders, distributing the decision-making responsibility to more knowledgeable people; (c) uses monetized representations that are important for assessing decisions in a unified manner; and (d) enables decision reuse and documentation. Conclusions The results of the study suggest that architectural decision-making can benefit from treating this activity as a financial investment. The various benefits that have been identified from mixing financial and technological aspects are well-accepted from industrial stakeholders

The Perception of Technical Debt in the Embedded Systems Domain:An Industrial Case Study

Technical Debt Management (TDM) has drawn the attention of software industries during the last years, including embedded systems. However, we currently lack an overview of how practitioners from this application domain perceive technical debt. To this end, we conducted a multiple case study in the embedded systems industry, to investigate: (a) the expected life-time of components that have TD, (b) the most frequently occurring types of TD in them, and (c) the significance of TD against run-time quality attributes. The case study was performed on seven embedded systems industries (telecommunications, printing, smart manufacturing, sensors, etc.) from five countries (Greece, Netherlands, Sweden, Austria, and Finland). The results of the case study suggest that: (a) maintainability is more seriously considered when the expected lifetime of components is larger than ten years, (b) the most frequent types of debt are test, architectural, and code debt, and (c) in embedded systems the run-time qualities are prioritized compared to design-time qualities that are usually associated with TD. The obtained results can be useful for both researchers and practitioners: the former can focus their research on the most industrially-relevant aspects of TD, whereas the latter can be informed about the most common types of TD and how to focus their TDM processes

On energy debt: Managing consumption on evolving software

This paper introduces the concept of energy debt: a new metric, reflecting the implied cost in terms of energy consumption over time, of choosing a flawed implementation of a software system rather than a more robust, yet possibly time consuming, approach. A flawed implementation is considered to contain code smells, known to have a negative influence on the energy consumption. Similar to technical debt, if energy debt is not properly addressed, it can accumulate an energy "interest". This interest will keep increasing as new versions of the software are released, and eventually reach a point where the interest will be higher than the initial energy debt. Addressing the issues/smells at such a point can remove energy debt, at the cost of having already consumed a significant amount of energy which can translate into high costs. We present all underlying concepts of energy debt, bridging the connection with the existing concept of technical debt and show how to compute the energy debt through a motivational example.This work is financed by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia, within project UIDB/50014/2020. The first author is also financed by FCT grant SFRH/BD/132485/2017. The last author is also supported by operation Centro-01-0145-FEDER-000019 - C4 - Centro de Competências em Cloud Computing, cofinanced by the European Regional Development Fund (ERDF) through the Programa Operacional Regional do Centro (Centro 2020), in the scope of the Sistema de Apoio à Investigação Científica e Tecnológica - Programas Integrados de IC&DT

E-Debitum: managing software energy debt

35th IEEE/ACM International Conference on Automated Software Engineering Workshops (ASEW ’20) - International Workshop on Sustainable Software Engineering (SUSTAIN-SE)This paper extends previous work on the concept of a new software energy metric: Energy Debt. This metric is a reflection on the implied cost, in terms of energy consumption over time, of choosing an energy flawed software implementation over a more robust and efficient, yet time consuming, approach. This paper presents the implementation a SonarQube tool called E-Debitum which calculates the energy debt of Android applications throughout their versions. This plugin uses a robust, well defined, and extendable smell catalogue based on current green software literature, with each smell defining the potential energy savings. To conclude, an experimental validation of E-Debitum was executed on 3 popular Android applications with various releases, showing how their energy debt fluctuated throughout releases.This work is financed by National Funds through the Portuguese funding agency, FCT -Fundação para a Ciência e a Tecnologia within project UIDB/50014/2020

The Financial Aspect of Managing Technical Debt: A Systematic Literature Review

Context Technical debt is a software engineering metaphor, referring to the eventual financial consequences of trade-offs between shrinking product time to market and poorly specifying, or implementing a software product, throughout all development phases. Based on its inter-disciplinary nature, i.e. software engineering and economics, research on managing technical debt should be balanced between software engineering and economic theories. Objective The aim of this study is to analyze research efforts on technical debt, by focusing on their financial aspect. Specifically, the analysis is carried out with respect to: (a) how financial aspects are defined in the context of technical debt and (b) how they relate to the underlying software engineering concepts. Method In order to achieve the abovementioned goals, we employed a standard method for SLRs and applied it on studies retrieved from seven general-scope digital libraries. In total we selected 69 studies relevant to the financial aspect of technical debt. Results The most common financial terms that are used in technical debt research are principal and interest, whereas the financial approaches that have been more frequently applied for managing technical debt are real options, portfolio management, cost/benefit analysis and value-based analysis. However, the application of such approaches lacks consistency, i.e., the same approach is differently applied in different studies, and in some cases lacks a clear mapping between financial and software engineering concepts. Conclusion The results are expected to prove beneficial for the communication between technical managers and project managers, in the sense that they will provide a common vocabulary, and will help in setting up quality-related goals, during software development. To achieve this we introduce: (a) a glossary of terms and (b) a classification scheme for financial approaches used for managing technical debt. Based on these, we have been able to underline interesting implications for researchers and practitioners