While the study of psychology has offered little in the way of explaining the creative process, Koestler examines the idea that we are at our most creative when rational thought is suspended--for example, in dreams and trancelike states. All who read The Act of Creation will find it a compelling and illuminating book.

The Act of Creation

The Analysis of Time Series: An Introduction, 4th edn. By C. Chatfield. ISBN 0 412 31820 2. Chapman and Hall, London, 1989. 242 pp. £13.50.

The Analysis of Time Series: An Introduction

This book gathers chapters from some of the top international empirical software engineering researchers focusing on the practical knowledge necessary for conducting, reporting and using empirical methods in software engineering. Topics and features include guidance on how to design, conduct and report empirical studies. The volume also provides information across a range of techniques, methods and qualitative and quantitative issues to help build a toolkit applicable to the diverse software development contexts

/pdf/guide-to-advanced-empirical-software-engineering-2f0my2wuh8.pdf

Guide to Advanced Empirical Software Engineering

Predicting the incidence of faults in code has been commonly associated with measuring complexity. In this paper, we propose complexity metrics that are based on the code change process instead of on the code. We conjecture that a complex code change process negatively affects its product, i.e., the software system. We validate our hypothesis empirically through a case study using data derived from the change history for six large open source projects. Our case study shows that our change complexity metrics are better predictors of fault potential in comparison to other well-known historical predictors of faults, i.e., prior modifications and prior faults.

Predicting faults using the complexity of code changes

Most studies of software evolution have been performed on systems developed within a single company using traditional management techniques. With the widespread availability of several large software systems that have been developed using an "open source" development approach, we now have a chance to examine these systems in detail, and see if their evolutionary narratives are significantly different from commercially developed systems. The paper summarizes our preliminary investigations into the evolution of the best known open source system: the Linux operating system kernel. Because Linux is large (over two million lines of code in the most recent version) and because its development model is not as tightly planned and managed as most industrial software processes, we had expected to find that Linux was growing more slowly as it got bigger and more complex. Instead, we have found that Linux has been growing at a super-linear rate for several years. The authors explore the evolution of the Linux kernel both at the system level and within the major subsystems, and they discuss why they think Linux continues to exhibit such strong growth.

/pdf/evolution-in-open-source-software-a-case-study-17fefefo4f.pdf

Evolution in open source software: a case study

The process of E-type software development and evolution has proven most difficult to improve, possibly due to the fact that the process is a multi-input, multi-output system involving feedback at many levels. This observation, first recorded in the early 1970s during an extended study of OS/360 evolution, was recently captured in a FEAST (Feedback, Evolution And Software Technology) hypothesis: a hypothesis being studied in on-going two-year project, FEAST/1. Preliminary conclusions based on a study of a financial transaction system-Logica's Fastwire (FW)-are outlined and compared with those reached during the earlier OS/360 study. The new analysis supports, or better does not contradict, the laws of software evolution, suggesting that the 1970s approach to metric analysis of software evolution is still relevant today. It is hoped that FEAST/1 will provide a foundation for mastering the feedback aspects of the software evolution process, opening up new paths for process modelling and improvement.

https://users.ece.utexas.edu/~perry/work/papers/feast1.pdf

Metrics and laws of software evolution-the nineties view

The past two decades have seen increasing sophistication in software work. Now and in the future, the work of both practitioners and researchers would be helped by a more objective and finer granularity recognition of types of software evolution and software maintenance activities as actually done. To these ends, this paper proposes a clarifying redefinition of the types of software evolution and software maintenance. The paper bases the proposed classification not on people's intentions but upon objective evidence of maintainers' activities ascertainable from observation of activities and artifacts, and/or a before and after comparison of the software documentation. The classification includes taking into account in a semi-hierarchical manner evidence of the change or lack thereof in: (1) the software, (2) the documentation, (3) the properties of the software, and (4) the customer-experienced functionality. A comparison is made with other classifications and typologies. The paper provides a classified list of maintenance activities and a condensed decision tree as a summary guide to the proposed evidence-based classification of the types of software evolution and software maintenance. Copyright © 2001 John Wiley & Sons, Ltd.

/pdf/types-of-software-evolution-and-software-maintenance-3qxqpldt6g.pdf

Types of software evolution and software maintenance

When first formulated in the early seventies, the i>laws of software evolution were, for a number of reasons, not widely accepted as relevant to software engineering practice. Over the years, however, they have gradually become recognised as providing useful inputs to understanding of the software process. Now eight in number, they have been supplemented by the software uncertainty principle and the FEAST (i>Feedback, i>Evolution i>And i>Software i>Technology) hypothesis. Based on all these and on the further results of the FEAST research projects this paper develops and presents some fifty rules for application in software system process planning and management and indicates tools available or that could usefully be developed to support their application. The listing is structured according to the laws that encapsulate the observed phenomena and that lead to the recommendations. Each sublist is preceded by a textual discussion providing at least some of the reasoning that has led to the recommended procedures. The references direct the interested reader to the literature that records observed behaviours, interpretations, models and metrics obtained from industrially evolved systems, and from which the recommendations were derived.

Rules and Tools for Software Evolution Planning and Management

In the context of a hypothesis attributing the slow progress in achieving major global software process improvement, in part, to overlooking the role of feedback in that process, the FEAST/1 project is studying the impact of feedback on software evolution. Amongst its activities the project is analysing metrics of the evolution of several industrial systems, ranging from a financial transaction system to a very large real time system. The similarities which have emerged from a comparison of evolution metrics from several systems, support conclusions reached in a 1970s study of OS/360 evolution. The latest results suggest some refinement of earlier conclusions but indicate that both the metrics and the conclusions derived from them must be taken into account in the planning and implementation of successful software maintenance. Papers discussing the FEAST/1 results may accessed via the FEAST web page [fwp98].

Juan F. Ramil

Papers

Metrics and laws of software evolution-the nineties view

Types of software evolution and software maintenance

Rules and Tools for Software Evolution Planning and Management

Implications of evolution metrics on software maintenance

Software evolution: background, theory, practice