Technical Debt Prioritization: State of the Art. A Systematic Literature Review

Background. Software companies need to manage and refactor Technical Debt issues. Therefore, it is necessary to understand if and when refactoring Technical Debt should be prioritized with respect to developing features or fixing bugs. Objective. The goal of this study is to investigate the existing body of knowledge in software engineering to understand what Technical Debt prioritization approaches have been proposed in research and industry. Method. We conducted a Systematic Literature Review among 384 unique papers published until 2018, following a consolidated methodology applied in Software Engineering. We included 38 primary studies. Results. Different approaches have been proposed for Technical Debt prioritization, all having different goals and optimizing on different criteria. The proposed measures capture only a small part of the plethora of factors used to prioritize Technical Debt qualitatively in practice. We report an impact map of such factors. However, there is a lack of empirical and validated set of tools. Conclusion. We observed that technical Debt prioritization research is preliminary and there is no consensus on what are the important factors and how to measure them. Consequently, we cannot consider current research conclusive and in this paper, we outline different directions for necessary future investigations

Modeling the complex dynamics of enzyme-pathway coevolution.

Peer reviewedPostprin

Ecosystem-inspired enterprise modelling framework for collaborative and networked manufacturing systems

Rapid changes in the open manufacturing environment are imminent due to the increase of customer demand, global competition, and digital fusion. This has exponentially increased both complexity and uncertainty in the manufacturing landscape, creating serious challenges for competitive enterprises. For enterprises to remain competitive, analysing manufacturing activities and designing systems to address emergent needs, in a timely and efficient manner, is understood to be crucial. However, existing analysis and design approaches adopt a narrow diagnostic focus on either managerial or engineering aspects and neglect to consider the holistic complex behaviour of enterprises in a collaborative manufacturing network (CMN). It has been suggested that reflecting upon ecosystem theory may bring a better understanding of how to analyse the CMN. The research presented in this paper draws on a theoretical discussion with aim to demonstrate a facilitating approach to those analysis and design tasks. This approach was later operationalised using enterprise modelling (EM) techniques in a novel, developed framework that enhanced systematic analysis, design, and business-IT alignment. It is expected that this research view is opening a new field of investigation

A taxonomy of asymmetric requirements aspects

The early aspects community has received increasing attention among researchers and practitioners, and has grown a set of meaningful terminology and concepts in recent years, including the notion of requirements aspects. Aspects at the requirements level present stakeholder concerns that crosscut the problem domain, with the potential for a broad impact on questions of scoping, prioritization, and architectural design. Although many existing requirements engineering approaches advocate and advertise an integral support of early aspects analysis, one challenge is that the notion of a requirements aspect is not yet well established to efficaciously serve the community. Instead of defining the term once and for all in a normally arduous and unproductive conceptual unification stage, we present a preliminary taxonomy based on the literature survey to show the different features of an asymmetric requirements aspect. Existing approaches that handle requirements aspects are compared and classified according to the proposed taxonomy. In addition,we study crosscutting security requirements to exemplify the taxonomy's use, substantiate its value, and explore its future directions

Structural dynamics in the evolution of a bilobed protein scaffold

Novel biophysical tools allow the structural dynamics of proteins and the regulation of such dynamics by binding partners to be explored in unprecedented detail. Although this has provided critical insights into protein function, the means by which structural dynamics direct protein evolution remain poorly understood. Here, we investigated how proteins with a bilobed structure, composed of two related domains from the periplasmic-binding protein–like II domain family, have undergone divergent evolution, leading to adaptation of their structural dynamics. We performed a structural analysis on ∼600 bilobed proteins with a common primordial structural core, which we complemented with biophysical studies to explore the structural dynamics of selected examples by single-molecule Förster resonance energy transfer and Hydrogen–Deuterium exchange mass spectrometry. We show that evolutionary modifications of the structural core, largely at its termini, enable distinct structural dynamics, allowing the diversification of these proteins into transcription factors, enzymes, and extracytoplasmic transport-related proteins. Structural embellishments of the core created interdomain interactions that stabilized structural states, reshaping the active site geometry, and ultimately altered substrate specificity. Our findings reveal an as-yet-unrecognized mechanism for the emergence of functional promiscuity during long periods of evolution and are applicable to a large number of domain architectures

A conceptual system design and managerial complexity competency model

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Complex adaptive systems are usually difficult to design and control. There are several particular methods for coping with complexity, but there is no general approach to build complex adaptive systems. The challenges of designing complex adaptive systems in a highly dynamic world drive the need for anticipatory capacity within engineering organizations, with a goal of enabling the design of systems that can cope with an unpredictable environment. This thesis explores this question of enhancing anticipatory capacity through the study of a complex adaptive system design methodology and complexity management competencies. A general introduction to challenges and issues in complex adaptive systems design is given, since a good understanding of the industrial context is considered necessary in order to avoid oversimplification of the problem, neglecting certain important factors and being unaware of important influences and relationships. In addition, a general introduction to complex thinking is given, since designing complex adaptive systems requires a non-classical thought, while practical notions of complexity theory and design are put forward. Building on these, the research proposes a Complex Systems Life-Cycle Understanding and Design (CXLUD) methodology to aid system architects and engineers in the design and control of complex adaptive systems. Starting from a creative anticipation construct - a loosening mechanism to allow for more options to be considered, the methodology proposes a conceptual framework and a series of stages to follow to find proper mechanisms that will promote elements to desired solutions by actively interacting among themselves. To illustrate the methodology, a financial systemic risks infrastructure systems architecture development case study is presented. The final part of this thesis develops a conceptual model to analyse managerial complexity competency model from a qualitative phenomenological study perspective. The model developed in this research is called Understanding-Perception-Action (UPA) managerial complexity competency model. The results of this competency model can be used to help ease project manager’s transition into complex adaptive projects, as well as serve as a foundation to launch qualitative and quantitative research into this area of project complexity management

Essays on Business Value Creation in Digital Platform Ecosystems

Digital platforms and the surrounding ecosystems have garnered great interest from researchers and practitioners. Notwithstanding this attention, it remains unclear how and when digital platforms create business value for platform owners and complementors. This three-essay dissertation focuses on understanding business value creation in digital platform ecosystems. The first essay reviews and synthesizes literature across disciplines and offers an integrative framework of digital platform business value. Advised by the findings from the review, the second and third essays focus on the value creation for platform complementors. The second essay examines how IT startups entering a platform ecosystem at different times can strategically design their products (i.e., product diversification across platform architectural layers and product differentiation) to gain competitive advantages. Longitudinal evidence from the Hadoop ecosystem demonstrates that product diversification has an inverted U-shaped relationship with complementors success, and such an effect is more salient for earlier entrants than later entrants. Earlier entrants should develop products that are similar to other ecosystem competitors to reduce uncertainty whereas later entrants are advised to explore market niche and differentiate their products.The third essay investigates how platform complementors strategies and products co-evolve over time in the co-created ecosystem network environment. Our longitudinal analysis of the Hadoop ecosystem indicates that complementors technological architecture coverage and alliance exploration strategies increase their product evolution rate. In turn, complementors with faster product evolution are more likely to explore new partners but less likely to cover a wider range of the focal platforms technological layers in subsequent periods. Network density, co-created by all platform complementors, weakens the effects of complementors strategies on their product evolution but amplifies the effects of past product evolutions on strategies.This three-essay dissertation uncovers various understudied competitive strategies in the digital platform context and enriches our understanding of business value creation in digital platform ecosystems

Strategy-focused architecture investment decisions

The thesis considers how a systematic approach for evaluating architecture investments can lead to decisions that are driven by business preferences rather than by personal incentives. A decision to invest in software-architecture requires systematic evaluation of the trade-off between strategic long-term benefits of architecture on the business and short term investment. It typically is a decision that is difficult to explain and quantify. In this sense, it is not surprising that such a decision is often driven by personal incentives or strong leadership of deciders, architects and managers, leading to suboptimal decision-making process in the organization. This PhD thesis proposes a way in which to support the decision to invest in architecture by linking the architecture improvements to the business strategy and taking into consideration the human aspects. We follow the iterative study design process including several real-life case studies, multiple interviews, and an experiment. In the first case study, we investigate how practitioners make a decision on architecture investment with a focus on how the decision process can be improved in industrial practice. To support the decision process in an objective way, we propose to use arguments based on real options theory. The evaluation by practitioners disclosed that including such economics of architecture is necessary but not sufficient for decision making. To better understand the information needs for decision making we conducted field interviews on the kinds of information that architects and managers need. In a subsequent experiment we tested whether which kind of information is actually used in decision making. As expected, the professionals tend to use just a few information types for decision making. However, our results suggest that additional quantified information was used by participants with longer development experience and under time pressure. Based upon the experimental findings we propose a concept to quantify the customer value of architecture. Despite the positive evaluation, the practitioners asked for further improvements to translate the architecture changes directly to the economic value. Ultimately, based on the findings from the preceding studies we propose a comprehensive approach to support objective architecture decision making; we label it Strategy-focused Architecture (StArch). Adopting strategic management tools, strategy map and balanced scorecards, we provide step-by-step guidance to assess the economic benefits of architecture improvements aligned with the strategic business objectives