Dong Shao

SCRUM-PSP: Embracing Process Agility and Discipline

With the research and debates on software process, the mainstream software processes can be grouped into two categories, the plan-driven (disciplined) processes and the agile processes. In terms of the classification, personal software process (PSP) is a typical plan-driven process while SCRUM is an agile-style instance. Although they are distinct from each other per se, our research found that PSP and SCRUM may also complement each other when SCRUM provides an agile process management framework, and PSP provides the skills and disciplines that a qualified team member needs to estimate, plan and manage his/her job. This paper proposes an integrated process model, SCRUM-PSP, which combines the strengths of each. We also verified that this integrated process by adopting it into a real project environment where typical agile processes are favored, i.e. change-prone requirements, rapid development, fast delivery, etc. As a result, manageability and predictability which traditional plan-driven processes usually benefit can also be achieved. The work described in this paper is a worthy attempt to embrace both process agility and discipline.

Empirical studies of embedded software development using agile methods: a systematic review

Agile approaches are proved by numerous case studies and reports to be effective and constructive in desktop software development. However, the situation is quite different in the embedded world due to the unique characteristics of the embedded software projects, which bring many difficulties to developers. And little is known about the current application status of agile methods to cope with this special domain. In this paper, a systematic review was conducted to explore the particularity of the embedded software development and the relevant solutions using agile methods and practices. The result will supply a guideline to choose the appropriate agile elements to deal with the challenges derived from embedded characteristics.

Improving PSP education by pairing: an empirical study

Handling large-sized classes and maintaining students involvement are two of the major challenges in Personal Software Process (PSP) education in universities. In order to tackle these two challenges, we adapted and incorporated some typical practices of Pair Programming (PP) into the PSP class at summer school in Software Institute of Nanjing University in 2010, and received positive results, such as higher students involvement and conformity of process discipline, as well as (half) workload reduction in evaluating assignments. However, the experiment did not confirm the improved performance of the paired students as expected. Based on the experience and feedbacks, we improved this approach in our PSP course in 2011. Accordingly, by analyzing the previous experiment results, we redesigned the experiment with a number of improvements, such as lab environment, evaluation methods and student selection, to further investigate the effects of this approach in PSP education, in particular students performance. We also introduced several new metrics to enable the comparison analysis of the data collected from both paired students and solo students. The new experiment confirms the value of pairing practices in PSP education. The results show that in PSP class, compared to solo students, paired students can achieve better performance in terms of program quality and exam scores.

Delivering PSP course in tertiary education environment: Challenges and solution

Nowadays, many universities include Personal Software Process (PSP) into their software engineering curriculum. However, delivering PSP course in tertiary education environment always faces at least two challenges. Firstly, in a typical PSP course in education environment, one teacher may teach much more students than a typical PSP class in industry, hence it is extremely difficult to provide evaluation of students assignments in time. Secondly, participation of students in university often has significantly different characteristics compared to those trainees who had industry experiences. Based on education practice in Software Institute of Nanjing University, this paper proposed an approach to teaching PSP in tertiary education environment with higher efficiency and effectiveness. In this approach, a complete PSP course is delivered and cooperative learning (in pair) is encouraged. Besides, an evaluation team is established to provide timely evaluation on students submissions and to help students correct their development behaviors. To validate this teaching approach, we conducted an experiment which involved all the freshman students enrolled in software engineering. We compared some process data collected from the submissions of both groups (individual and pair) of students. The results of the experiment show that the load of students submissions reduced by half while students interest of learning increased.

CMMI guided process improvement for DevOps projects: an exploratory case study

Very recently, an increasing number of software companies adopted DevOps to adapt themselves to the ever-changing business environment. While it is important to mature adoption of the DevOps for these companies, no dedicated maturity models for DevOps exist. Meanwhile, maturity models such as CMMI models have demonstrated their effects in the traditional paradigm of software industry, however, it is not clear whether the CMMI models could guide the improvements with the context of DevOps. This paper reports a case study aiming at evaluating the feasibility to apply the CMMI models to guide process improvement for DevOps projects and identifying possible gaps. Using a structured method(i.e., SCAMPI C), we conducted a case study by interviewing four employees from one DevOps project. Based on evidence we collected in the case study, we managed to characterize the maturity/capability of the DevOps project, which implies the possibility to use the CMMI models to appraise the current processes in this DevOps project and guide future improvements. Meanwhile, several gaps also are identified between the CMMI models and the DevOps mode. In this sense, the CMMI models could be taken as a good foundation to design suitable maturity models so as to guide process improvement for projects adopting the DevOps.

An Empirical Evaluation of Capture-Recapture Estimators in Software Inspection

Context: Capture-recapture approach has been adopted in software inspection for decades for estimating remaining defects and supporting post-inspection decisions. A number of capture-recapture models and estimators have been borrowed from other disciplines (e.g., Biology and social sciences) and applied in software inspections. These models and estimators were created with different assumptions and the violation to these assumptions may lead to invalid application. Most of the reported empirical evaluations of the capture-recapture models and estimators used relatively small data sets (i.e., Small number of inspectors and/or defects), which leads varying conclusions. Objective: The research reported in this paper aims to better understand this approach for software inspection, and the efficacy of the models and estimators in particular, with large data sets. Method: We carried out an empirical study that evaluated several typical capture-recapture estimators (i.e., M0-ML, Mt-ML, Mt-CH, Mh-CH and Mh-JK). The study employed 57 student inspectors in reviewing software requirement specification and formed 1000 virtual teams at each team size in the post statistic testing. Results: The data analysis indicates that: 1) M0-ML and Mt-ML could not generate accurate estimates even with many inspectors. 2) All estimators suffer high level of failure rate with few inspectors. 3) For a small team, estimator Mh-CH performs the best, while with many inspectors, Mt-CH and Mh-JK perform better regarding the accuracy and the failure rate. Conclusion: Our work reveals that no estimator was superior to others under all situations. With an increased team size, estimates generated by estimator Mt-CH and Mh-JK turn to be more accurate than others. While, M0-ML and Mt-ML are able to offer reference value to support post-inspection because of their convergent underestimates.

Where does experience matter in software process education? An experience report

In order to enhance the understanding of important concepts and strengthen the awareness of software process, we designed a special project-practicing course in Nanjing University as an attempt to solve typical issues in these courses (e.g., focusing on aspects of software process, participation, limited time in a regular semester, etc.). The course is composed of 6-hour lecture and 32-hour bidding game. Preliminary results indicated several advantages with this new education approach on process-specific practicing course, which we already reported on CSEE&T2013. Since this course has been delivered to students from school (less experiences) and industry (more experiences), we noticed students different performances on this course. In this paper, we collected course results from six classes, based on a comprehensive analysis from 8 different aspects; we try to understand where “EXPERIENCE” impacts students difference performance and benefit from the understanding to improve our education on software engineering.

Delivering Software Process-Specific Project Courses in Tertiary Education Environment: Challenges and Solution

The importance of delivering software process courses to software engineering students has been more and more recognized in China in recent years. However, students usually cannot fully appreciate the value of software process courses by only learning methodology and principle in the classroom. Therefore, a process-specific project course was designed to fill the gap between the software process theoretical and experiential knowledge. But to design the course also has many challenges, such as: to provide enough guideline for students; to monitor every process task; to gather and use the process data, especially considering the large class size. We designed a summer school 6-weeks project course in Nanjing University based on TSP (Team Software Process) methodology. To support the course, we developed a supporting tool, the Advance Process Improvement Solution (APIS), which can record and use historical data, support teamwork, and provide process data to both students and teachers in real time. This paper describes the methodology, course organization, supporting tool, and evaluation in details. Based on our two years experience, this course plays a key role for SE students to better understand software process.

Can software engineering students program defect-free?: an educational approach

Quality of software intensive systems is the priority con- cern and focus in industry and the research community. In practice, the increasing demand for experienced software developers in industry requires developers mature themselves in a timely manner to be able to produce high quality pro- grams. It has become a realistic challenge to both software engineering educators and researchers. To address this challenge, we devised the PSP+ process, in particular for students majored in software engineering, that enhances the original PSP (Personal Software Process) with an ultimate goal at Defect-Free Programming (DFP). Based on the original PSP, the PSP+ incorporates a set of explicitly defined practices to facilitate experience gaining and sharing among students with the special concern on DFP. This paper elaborates the proposed PSP+ process and also reports a con- trolled experiment that was designed and executed to investigate the effectiveness of the PSP+ within an educational setting. The experiment results indicate that students using the PSP+ are more likely to perform high quality program- ming without extra effort. They also gain higher confidence with DFP compared to those using the original PSP.

An introductory software engineering course for software engineering program

One important issue in undergraduate software engineering curriculum is how to help students establish the concept of software engineering at the beginning of software engineering undergraduate program and to provide a reasonable basis of knowledge and skills for subsequent courses. The Computing and Software Engineering (CSE), a three-semester course, is designed as the introductory course for undergraduate software engineering program at NJU in China; it tries to help students learn the comprehensive knowledge and skills in constructing small-to-medium size software. The course includes not only technical topics, such as programming and software development technology, but also professionalism and teamwork through constructing different scales of software. The knowledge is organized with the complete software example development demonstration, which makes it easier for students to synthesize all knowledge related in software development. CSE has been executed from 2009, and it has been refined according to feedback from students, lecturers and TAs. This paper describes the design and teaching practice of CSE.