As software systems change and evolve over time regression tests have to be run to validate these changes. Regression testing is an expensive but essential activity in software maintenance. The purpose of this paper is to compare a new regression test selection model called ReTSE with Pythia. The ReTSE model uses decomposition slicing in order to identify the relevant regression tests. Decomposition slicing provides a technique that is capable of identifying the unchanged parts of a system. Pythia is a regression test selection technique based on textual differencing. Both techniques are compare using a Power program taken from Vokolos and Frankl’s paper. The analysis of this comparison has shown promising results in reducing the number of tests to be run after changes are introduced.

Resource scheduling is concerned with selecting the most appropriate resources to meet the needs of consumers. This is a complex task in Cloud Computing because of the large amount of available resources such as applications and data storage facilities. This is compounded further when security issues and quality of service are also factored in. A Scheduling Security Model (SSM) for Cloud Computing has been developed to address these issues. This paper will apply the SSM model on some examples with different scenarios to investigate the cost and the effect on the service requested by customers.

Resource scheduling in cloud computing is a complex task due to the number and variety of resources available and the volatility of usage-patterns of resources considering that the resource setting is on the service provider. This compounded further when security issues are also factored in. This paper provide a Systematic Literature Review (SLR) that will help to identify as much prior relevant research that has been done in the area of research topic. Also, all papers that are found from the search will be classified into groups to stand on the current situation and to identify possible existing gaps.

This paper explores from the teachers’ point of view how new interactive technology for teaching the Islamic Prayer in Primary Schools can enhance engagement and interaction in the classroom.  An interesting aspect of the research in Human Computer Interaction (HCI) is that it focuses on both the human and computer perspectives. From the technological side, the focus is on how the computer hardware can improve the quality of HCI. Computer graphics for example, aims to ensure the graphics of a game is of a good standard so users will enjoy their game play, whilst operating systems are also considered in order to ensure good multiprocessing and to tune system response times to human interaction times. From the human side, HCI is primarily focused on the cognitive relationship with computers by ensuring the design is suitable for humans to operate successfully. The interactive Islamic Prayer (iIP) system designed for Xbox 360 Kinect with this specific goal in mind, and as an alternative to traditional learning methods. The participants for the research are Saudi Arabian primary school teachers in Jeddah, who currently teach the prayer using a traditional method. The teachers were experienced in all methods of learning (the controlled traditional method, and the iIP software) before making an informed decision on which method they prefer through a qualitative analysis of the participants teaching experiences. In addition, observations of each teaching session were organized to see how the methods engage the learners. The results show that learning by doing is extremely effective in helping the pupil’ practice, interact and remember the prayer movements.

Semantic-based user input validation of web applications is important because of the central role these applications play in our daily lives. An example of such a process is in rejecting a four-digit number as an input that represents the age of a web application user. Testing professionals must write test cases that can be used to check if a web application can handle semantically invalid inputs. Most of the current approaches for test case generation for web applications do not consider the semantics of inputs. And for approaches that do consider input semantics, test case generation is done manually. This paper defines a process that can be used to automate and in some cases, semi-automate the generation of test cases to assess semantic-based user input validation of web applications (TCSUIV). To prove the usefulness of the process in this paper, it is applied to case study web page. A prototype tool has been built also to show the applicability of this paper process for test case generation for web application.

Regression testing is expensive but an essential activity in software maintenance. Regression testing validates modified software and ensure that the modified parts of the program do not introduce unexpected errors. This paper briefly describes an overview of regression testing specifically regression test selection techniques. Most regression test selection techniques are based on program slicing techniques.

Background: The Islamic Prayer is central to the Islam religion and is a requirement for all Muslims to learn and perform properly. Teaching the Islamic Prayer had traditionally been through the use of textbooks. Aims: This paper describes the design and implementation of the IIP (interactive Islamic Prayer) system to teach the Islamic prayer using Virtual Environments and interactive technologies. Method: The approach taken was to first define the various elements that make up the Islamic Prayer (positions, verbal statements and units). This is then captured in software that uses the Microsoft Windows Kinect system. Results: The Islamic Prayer sequences were successfully captured and implemented in the iIP system. Conclusions: The iIP system design and implementation using Microsoft Windows Kinect system was described. This was based on the definition of the different elements of the Islamic Prayer.

The development of diverse human skills and abilities is a necessity, especially in the construction and development of the learning process. Furthermore, interactivity is an important new technology that has underpinned the learning process in recent years. This paper examines interactivity using a novel format of electronic lecturing. The Interactive Electronic Lecturing System is an application that offers interactivity between students and their lecturers by providing certain technologies. An experiment was conducted to check the level of interactivity with this system, in which mixed methods were adopted to examine the satisfaction of participants using the system. Thirty two students from the IT and Education departments of King Abdulaziz University (KAU) participated in the experiment and the result showed that the participants were satisfied and had a positive experience when using the IELS.

Evaluation is an essential part of creating and applying an interactive electronic lecture system (IELS).IELS is designed to enhance lecturing process for undergraduate students at King Abdulaziz University.To evaluate the IELS there are three main issues covered in this paper, namely IELS features, experiment design and research methods.IELS is integrated application that offers rich interactive components for users.The first issue is IELS features such as user accessibility, usability, learnability, interactivity, communication, satisfaction.The second issue is experimented design for evaluation IELS.Third issue describes how the data has been gathered and how the results are analysis.

The implementation of Virtual Environments has often been used within the educational domain. This study adopts a Virtual Environment (VE) setting for the specific purpose of teaching the Islamic prayer to primary school children. The interactive Islamic Prayer (iIP) system has been designed for the Xbox 360 Kinect and covers the various movements of the prayer in sequence. In doing so, the objective is to evaluate whether it would facilitate a "user-friendly" experience for the students, through direct interaction of mimicking the displayed movements during the prayer. Through a quantitative analysis of the participants' learning experiences, this study investigates the importance of designing and developing training software for the purpose of teaching the Islamic prayer, particularly in relation to those that adopt a Virtual Environment setting. As part of the data analysis, questionnaires were given to the participants to evaluate the usability, usefulness and overall learning experience of the iIP software. The results revealed participants held a positive perception and experience towards the iIP software and felt that this approach (learning by doing) was effective in helping them memorise the sequential prayer movements.

Use of multi-touch interfaces for collaborative software design has become increasingly important. Such surfaces can accommodate more than one user concurrently, which is particularly useful for collaboration. In this paper, the quality of collaborative software design using Unified Modeling Language (UML) was studied. In particular, we looked at if/how the quality of students' design diagrams could be enhanced in a contemporary multi-touch table environment, as opposed to a traditional PC based environment. The results showed that multi-touch environment increased the amount of physical interactions and subjects' engagement with the design activities. In addition, the multi-touch setting encouraged students to be engaged in a discursive conversation using "Creative Conflict" skills.

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The use of Multi-touch interfaces for collaborative learning has received significant attention. Their ability to synchronously accommodate multiple users is an advantage in co- located collaborative design tasks. This paper explores the potential of Multi-touch interfaces in collaborative Unified Modeling Language (UML) diagramming by comparing them to a PC- based tool and evaluating the collaborative learning skills and level of physical interaction in both conditions. The results indicate that even though participants conversed more in the PC- based condition, the use of the Multi-touch table increased the level of physical interaction and encouraged creative conflict skills amongst the team members. Introduction use of Multi-touch interfaces for collaborative learning has received significant attention, as they can accommodate more than one user at a time. This is particularly useful for learning through large, shared display systems, such as tabletops (Han 2005). Furthermore, the Multi-touch environment provides new opportunities for interaction between humans and computers. This area has been investigated by researchers from several different educational backgrounds, and they have found Multi-touch environments to be useful, as interaction

Introduction: Electronic Government (e-Government) is attracting the interest of governments around the globe due to its great importance in facilitating and providing services to its citizens. Although most of the countries place massive budgets and provide latest technologies, they face many obstacles, including the notable absence in the assessment of e-Government services. Therefore it becomes important to find ways of assessing e-Government services to determine if it reaches desired goals of their citizens. Aim: This research concentrates on assessment of e-Government services provided to citizens through the development, evaluation and analysis of a new framework. This framework is citizen centric and will help e-Government organizations to assess the strengths and weaknesses of their services. One of the main aspects of developing an assessment framework is to consider the citizens. The citizen is one of the reasons that drive such governments to put their services online as they are the targeted consumers. Therefore, finding ways of assessing their services is very crucial to achieve better results and citizens satisfaction. The IMGov Model is based around the concepts of four attributes (Input, Processing, Quality Control and Output). Each of those consists of set of factors that will be evaluated using a set of evaluation questions. As an example the quality control attribute includes factor that an organization has website content and a system that provide the services to the citizens. The new framework will be compared with existing frameworks. As this research concentrates on services assessment this comparison may be difficult because existing frameworks focus more on the process of how government achieve better e-Government from other perspectives such as technological, political, social and cultural. Method: Different methods will be adopted such as interviews, surveys (Quantitative, Qualitative) for garnering appropriate information and data by reviewing existing e-Government initiatives in different countries, reviewing wide collections on the existing research on the field and reviewing international standards and categorize them based on citizen centered approach. The actual evaluation can be through a carefully weighted average scheme or alternatively the results can be presented in term of Parallel Coordinates or Star Plots to allow as more in depth examination of the results. Result: This research will develop a conceptual framework to enable assessment of e-Government initiatives by evaluating services provided to citizens. This framework will then be evaluated using case study in Saudi Arabia. Conclusion: This research will produce adequate e-Government assessment measures for the services provided to citizens.

Centralized online reputation systems have been widely adopted by Internet companies to help users build trust, reduce information asymmetry and filter information. Research in this area to date has focused on analyzing the effectiveness of single-type systems, while less attention has been paid to the comparison of different systems. This paper proposes an analysis model that can classify and measure different reputation systems in the same context. The model divides reputation systems into five underlying components: input, processing, output, feedback loop and storage. A series of benchmark criteria is then defined based on the characteristics of each component. The model comprehensively analyzes most characteristics of centralized reputation systems and it takes both performance and costs of systems into consideration.

Meir M. ‘Manny’ Lehman studied mathematics at Imperial College London, where he was involved in the design of the Imperial College Computing Engine's Digital Computer Arithmetic Unit. He worked for Ferranti (1956–1957), the Scientific Department of Israel Ministry of Defence (1957–1964) and IBM (1964–1972). From 1972 to 2002 he was with Imperial College, where he was Head of Section and later Head of Department. In 2002 Prof. Manny Lehman moved to the School of Computing Science at Middlesex University. After retiring from Middlesex, he moved to Jerusalem, Israel, where he passed away on December 29, 2010. The Laws of Software Evolution are probably the best known result of Lehman's work. While it is not our intention to discuss these laws here, we would like to recall that, after the work of Lehman, software engineering at large has recognized that real-world software systems require continuous changes and enhancements to satisfy new and evolving user requirements and expectations, to adapt to new and emerging business models and organizations, to adhere to changing legislation, to cope with technology innovation and to preserve the system structure from deterioration. The Law of Continuing Change states: ‘A program that is used in a real-world environment necessarily must change or become progressively less useful in that environment.’ However, continuing change comes at a cost, for it needs to be managed and directed, as stated by the Law of Increasing Complexity: ‘As an evolving program changes, its structure tends to become more complex. Extra resources must be devoted to preserving and simplifying the structure.’ Unfortunately, managing continuous change is not easy, as software evolution is a self-regulating phenomenon resulting from superimposition of inertial, momentum and feedback effects. The Law of Large Program Evolution states: ‘Program evolution is a self-regulating process. System attributes such as size, time between releases and the number of reported errors is approximately invariant for each system release.’ Over the years, Lehman formulated a comprehensive set of eight laws, and for many of them an extensive body of supporting evidence has been developed. The laws have gradually become recognized as providing useful insights into the understanding the software process and have found their place in software engineering curricula at numerous universities across the world. The laws of software evolution are not the sole scientific achievement of Manny Lehman. Without any claim of completeness, we recall his Uncertainty Principle for Computer Application: ‘The outcome, in the real world, of software system operation is inherently uncertain with the precise area of uncertainty also unknown.’ This principle has motivated and informed all his research activity in software engineering, on the assumption that this discipline, as reflected in software development and evolution processes, and in the methods and tool used, is the means whereby uncertainty and consequences of uncertainty can be minimized. Also notable for its influence on the discipline of software engineering is his SPE classification which is mentioned in many software engineering texts. The classification identifies S-type programs that can be fully understood and specified formally; P-type programs that require an iterative process to identify a working solution; and, E-type programs that are embedded in the real world, becoming part of it, thereby requiring feedback systems that will allow the program and its environment to evolve in concert. The classification helped to address many of the pervasive issues related to the software process and was used as a basis for Manny's work on the relationship between specification and reification models and the various models of the software process that he presented at the initial Software Process Workshops. Manny Lehman spent the last part of his career developing models of a software process as a feedback system, convinced that real-world software evolution processes constitute multi-level, multi-loop, multi-agent feedback systems and must, in general, be treated as such to achieve significant process improvement for other than the most primitive processes. He stated that the self-dynamics a process develops over its first few releases takes over the behavioral trends of the system development, and the scope for maneuver, in terms of achievable system growth or evolution rate, for example, is more constrained than is normally assumed. In an interview released to for ACM Software Engineering Notes, Lehman summarized this concept in the statement ‘The process and system controls the managers rather than that the managers control the system.’ During his career Manny Lehman has received numerous awards from prestigious organizations, including the IEEE Computer Society ‘Harlan D. Mills Award’ in 2001 ‘For pioneering contributions to the empirical study of software processes and program evolution’ and the Re-engineering Forum ‘Stevens Award’ in 2003. He played a key part in establishing software engineering as a viable and vibrant discipline and participated in many conferences, symposia, workshops and other events, often both enriching and challenging perceived wisdom. Software engineering, like any other scientific discipline, is a fabric of ideas, which must be publicized, defended, sustained and translated into practice. Manny Lehman, with his many years of scientific commitment, has contributed to establishing a large and solid body of knowledge on software evolution and process not only through his research results, published in numerous books and articles, but also by his continuous collaboration with industry, active participation in associations and institutions, supervision and support of PhD students, and open and fertile exchange of ideas with other researchers and practitioners. We include at the end of this editorial a testimony from colleagues, former students, and friends who have appreciated Lehman as a person and as an inspired and inspiring teacher and researcher. With this brief editorial we celebrate both the value and legacy of the scientist and the man. Above all, we thank him for opening a new perspective that inspired a generation of practitioners and researchers in software maintenance and process improvement. Newton once said ‘If I have seen further than others, it is by standing upon the shoulders of giants.’ Thank you Manny, for allowing so many software engineering practitioners and researchers to climb on your shoulder to look at the future of software engineering! 'Manny Lehman was a true pioneer in the world of empirical software engineering. His early work (with Les Belady), making empirical observations on the evolution of OS360, set the stage for much of what was to come in empiricism. It certainly affected my thinking and the direction of my own work. He spent the better part of his career studying software evolution and gave the subject legitimacy. I worked closely with Manny (and Watts Humphrey, Barry Boehm, and Bill Riddle) on the original Software Process Achievement Award Committee for several years. He was always committed, insightful and dogged in his work and generous with his ideas. He will be sorely missed but his legacy lives on.' 'I met Manny for the first time in 1996, in Manchester, U.K., when he interviewed me for a research assistant position at his FEAST project at Imperial College. I was involved at the time in postgraduate study of control systems and Manny was interested in someone with that particular background. Manny came for another meeting at the UMIST Conference Center and took the opportunity to interview me there, saving me a trip to London. The interview must have gone well because after another interview with Professors Ber Rustem and Vic Stenning I was offered the job. My dream was ‘to do research’ but I was not totally clear what I was heading into. Coming from a different field, I did not know that I was going to work with the ‘Father of Software Evolution’. I worked for Manny until 2001, when I took a position at The Open University, U.K. I am grateful to Manny and to the other colleagues of the FEAST team, Professors Wlad Turski and Dewayne Perry, Drs Paul Wernick and Goel Kahen and for Manny's excellent secretary, Mrs. Siew Lim, for those formative years. Academically I was the most junior member of Manny's team. I was there, with a vast universe in from of me of things to learn …Yes, working with Manny and his distinguished colleagues at Imperial was a singular priviledge. Manny dressed modestly: dark trousers, a white or light-coloured shirt, and always wearing his Jewish kippah. He didn't like to be called ‘Professor’, asking always to be called ‘Manny’. Manny's smile was warm and welcoming. He treated with the same consideration the highest and the lowest around him. Manny's thought and convictions were original and he wasn't afraid to be openly critic of the buzzwords of the moment. He was concerned with big issues such as whether humanity would survive the so-called ‘software era’ or a software defect (an invalidated assumption) may bring to an end civilisation as we know it. Despite his deep thoughts and scientific aspirations, Manny enjoyed very much interacting with young researchers and students: he has himself a fresh mind and a young heart. He was strongly committed to work. When I knew him he had always at least one paper, proposal or paper ‘in production’. He was prepared to go as many times as needed through a draft and was welcoming comments and feedback. He has always prepared for scientific and will ‘fight’ with arguments every word in a joint writing of a paper if he felt strongly about something. For Manny, this intellectual ‘fight’ or struggle between colleagues was essential for learning something new. After a discussion, he was friendly as ever. Science is the universal language of those who sincerely search for the truth. Some have come to believe that to be a true scientist one must be atheist. This is very far from reality as Manny's life and accomplishments show. Manny was an orthodox Jew and profoundly believer in God. Once he said to me that his entire life has been a miracle and I believed him. He started his day very early in the morning by study of the Talmud. At arrival at his office he spent his first minutes in religious reading and prayer. A copy of one book of the Talmud was prominently visible in his office. For Manny there was no contradiction between faith and science. His observance of the Sabbath and the Jewish customs was strict: he won't accept even the most prestigious invitation if it was on a Saturday. He won't touch the most delicious meal if it wasn't kosher. Manny is an example for those who keep their religious faith in academic and industrial environments in the West which, sadly, have become hostile to religion in many subtle and non so subtle ways. Manny is a good example of what the great Louis Pasteur once said ‘Un peu de science éloigne de Dieu, mais beaucoup y ram éne.’ (‘A little of science separates from God, but a lot of science brings back to Him’.) It seems paradoxical that the ‘Father of Software Evolution’ had pioneered the evolution concept, given that Darwin's biological evolution concept has been used to undermine the belief that a Creator is at the origin of everything. I never discussed this with Manny. However, from what I could understand after five years of work with him was that Manny's view of evolution was deeply different to Darwinism. Manny always defended that the software evolution (i.e. the continual change and growth in functionality of E-type software) was a phenomenon of its own kind. Manny's evolution is not a blind process, but a process which is directed by humans, with humans and for humans. Human thought and intelligence pervade the evolution of software, as opposed to the Darwinist view that the process is driven by random variation. One could interpret, with hindsight, that Manny spoke of a ‘creationist-evolution’ or ‘intelligent-evolution’, in the sense that the human (the programmer, the manager, the user) drive the phenomenon. Moreover, Manny saw software evolution as an example of the evolution of artificial (i.e., man-made) systems. He strongly believed that the study of software evolution may illuminate other areas of human endeavour. Perhaps one day Manny will be recognised as the ‘Father of Artificial System Evolution’. Manny gave presentations with the same passion to a large audience or to a minuscule group. He always said: better to have a few interested people that an uninterested crowd. The research topic of software evolution has now become popular. Manny's work is frequently quoted but only very occasionally as main focus of the research. The world hasn't caught up with Manny, but it will. Manny's way of looking at the software phenomenon is perhaps still to be ‘discovered’ and his intuitions to be empirically evaluated and developed. Manny used the term ‘laws’ in his laws because, in his opinion, they reflected phenomenon outside the control of the individual programmer or software engineer. Release after release of a large system, programmers, managers and users may become ever more ‘prisoners’ of the software evolution and organisational inertia. The first seven laws can be seen, in this way, as pessimistic. For Manny, the hope was in the 8 th law: managers, programmers and users raise to contemplate the ‘global software process’ with all its feedback loops and intricacies in search for place to improve or tune the process. This vision still seems far from the day-to-day of the software organisations where often stakeholders need to hide deep in their trenches. Despite his scientific contributions, for those who knew Manny, what counted most was his great humanity. Above Manny's scientific and academic achievements, Manny was a loving husband and father, a demanding, strong, patient, compassionate and forgiving supervisor, and an excellent colleague. He should be remembered as a good man. May he rest in Peace.' 'Long before we met, I knew the classic Manny Lehman and Laszlo Belady paper on the development of the OS 360 operating system (Belady and Lehman 1976). In contrast to what was published then, the paper was based on the observation of a real large software project. In order to describe their observations, the authors coined the novel term ‘software evolution’. That was at a time when mainstream software engineering was dominated by the waterfall lifecycle and everything that did not fit waterfall was derisively dismissed as ‘hacking’. I met Manny Lehman personally for the first time in 1982, at the Rapid Prototyping Workshop (Squires, Zelkowitz, and Branstad 1982). Software prototyping emerged at about that time, and the workshop was addressing whether prototyping is really useful, how it fits it into the waterfall, and so forth. Among about eighty participants, Manny and I argued the following position: Waterfall does not work for large systems, an iterative process of software evolution is the only workable solution, and prototyping is a step in the right direction although it is insufficient as it contains only two iterations, one for the prototype and one for the final product. I got an impression that in the minds of many participants, we were throwbacks to hacking. The camaraderie under verbal bombardment was the beginning of our friendship that lasted more than 20 years. During those years, Manny produced an impressive list of papers that document the various aspects of software evolution. We met on many occasions at conferences in America or Europe and discussed developments in our field. Manny even showed up at one of my tutorials (Rajlich 1997) and put me into an awkward position to explain to him what software evolution is! I solved the problem by introducing Manny to the audience with a disclaimer: ‘He is the man who started this whole thing and he will correct whatever I say.’ I met Manny the last time in 2005 (First International IEEE Workshop on Software Evolvability 2005). By this time, software evolution was a respected and even indispensable software engineering field. However in their enthusiasm, some workshop participants tried to draw a parallel between software evolution and Darwinian evolution in biology. Again, Manny and myself argued a similar position: Software evolution is not Darwinian, there is no random mutation of programs (hopefully!) and no natural selection. Manny, it has been a joy to know you! Thanks to your vision and persistence, software evolution is placed firmly on the map of software engineering, to the great benefit of the whole software engineering community.' Belady LA, Lehman MM. A model of large program development. IBM Systems Journal 1976; 15(3):225–252. First International IEEE Workshop on Software Evolvability, 2011. 2005 [cited February 5 2011]. Available from http://homepages.feis.herts.ac.uk/∼comqcln/EN/evolvability_icsm.html. Rajlich V. Comprehension and evolution of legacy software (tutorial). Paper read at International Conference on Software Engineering ACM, 1997; 669–670. Squires SL, Zelkowitz M, Branstad M. Rapid prototyping workshop: overview. ACM SIGSOFT Software Engineering Notes 1982; 7(5):2. ‘Manny was a major contributor and inspiration for the activities of Durham University's Centre for Software Maintenance as well as at the annual Software Maintenance Workshops which formed a valuable bridge to industry. Manny was always welcome in Durham, so much so that, ready at all times, were his personal cutlery and crockery that met his kosher requirements. When Keith Bennett was starting the Journal of Software Maintenance, Manny contributed its first article. Similarly, Liz Burd and Malcolm Munro's research on program evolution was strongly motivated by his systems work, and these complementary views of evolution led to many fruitful discussions.’ ‘As a computer science student in the 70s and 80s, I had read and was deeply impressed by Manny's vision about bringing the Engineering ethos into the Software Production. Later on, I joined Imperial College, and so I saw Manny occasionally. However, out of shyness, and also because I was no longer working on Software Engineering, I never attempted to enter into a deeper conversation. But Manny went out of his way to make me feel welcome, when I happened to move into an office adjacent to his: He came into my office, and said that he was very happy to have me as a neighbour, since my name (Drossopoulou) reminded him of mutations (Drossophila), and through mutation it is that we achieve improvement.’ ‘Most people think of Manny as the guy who worked with Les Belady in analyzing the IBM OS/360 data and coming up with those Laws of Software Maintenance. But he was a tremendously wide-gauged person who made significant contributions and stimulating collaborations in software process as a lead founder of the International Software Process Workshop series, contributing such concepts as the inverted V-model; a leader in applying concepts of closed-loop feedback control to software engineering; and a pioneer in establishing an innovative teaching hospital approach to software engineering education at Imperial College, which was the inspiration for the real-client software engineering team project course we run at USC. His active mind, constructive spirit, and seminal contributions will live on after him.’ ‘Manny first came to Imperial as an undergraduate to study in the Maths department in the 1950s. After getting a degree he went on to design the Arithmetic and Logic Unit for ICCE II, the planned electronic valve successor to ICCE, the Imperial College Computing Engine for his PhD. This was followed by positions at Ferranti, the Israeli Ministry of Defence, and IBM. Manny returned to Imperial, joining the two year old Department of Computing and Control in 1972 as head of its Computing Section. In 1979 the Department of Computing came into existence and Manny became its first Head of Department, a post he held from 1979 to 1984. In his time in this role he brought considerable energy and commitment to the post, introducing many new initiatives and ideas. Manny's vision was of a department with a strong engineering focus and his influence is visible to this day. When Manny arrived the only taught programme was the MSc in Computing Science. Under his leadership, our first three and four year undergraduate degree programmes were developed. Our current, successful degrees are clearly direct descendants of these degree programmes. He also brought research funding into the department and set up the Imperial Software Technology Company. Under Manny's leadership the department made great strides in research as was evident in the department's top rating in the first Research Assessment Exercise.’ ‘Manny Lehmann is best known for his contributions to software engineering. However, Manny was also a hardware pioneer. While a PhD student at Imperial College in the mid 1950s, he worked alongside my dad Sidney Michaelson, and Keith Tocher, during the design and construction of the second Imperial College Computing Engine (ICCE2), a valve based computer. This influenced Manny's subsequent work at the Weizmann Institute on the Sabrac, Israel's first locally designed computer. You can find more details of the ICCE computers and Manny's account of SABRAC at: http://www.macs.hw.ac.uk/∼greg/icce/ Manny always spoke warmly of his experiences with early computers: perhaps this influenced his patient, painstaking and long sighted approach to software engineering.’ 'In 1987 I discovered a wonderful book: Program Evolution: Processes of Software Change, by Manny Lehman and Les Belady. My first ‘formal’ study session with Manny took place in his office at Imperial College in 1988 after I wrote to him asking some questions about his laws of evolution and the ideas explored in the book. Manny responded immediately inviting me to visit and ask the questions in person. Following a three-hour session which only covered the first few items on the list, he suggested we should continue to meet until we have exhausted all the questions. In subsequent sessions we continued to debate, explore and speculate. Manny was fond of the sessions and the questions, as they replicated the Jewish mode of study used in Yeshivas (Jewish houses of study), where a pair challenge each other's assumptions and thought processes employed in making sense of a particular idea or concept (somewhat akin to Pair Programming). The discussions were always thought provoking, and demanding, inevitably leading to further questions. After Manny joined us at Middlesex University to continue his research, he extended the scope of his enquiry to look into the role of assumptions in software development and at their influence on software failure. Manny estimated that in every ten lines of code was hidden at least one assumption that failed to fully comprehend the true scope of the problem, the requirements, or the real world in which it was situated. Such assumptions would often be responsible for the ultimate failure of the software. We never managed to finish addressing all the questions on the list, but our discussions proved provoking, enriching, and liberating. Manny was compassionate, charming, supportive and curious, encouraging others to achieve and challenge. His incisive contributions to software engineering in terms of knowledge, thinking process, and enthusiasm leave a tremendously rich legacy spurring us on to ask the next question …' 'For many years Manny and I were external examiners for the Institute of Systems Sciences at the National University of Singapore, and enjoyed many joint visits there. The Institute teaches a wide range of business-oriented software courses at Masters level, and Manny was always a passionate advocate of the concepts of software evolution and software engineering generally. During our visits, he and I also discussed a broad variety of other questions, notably including Judaism. As you know, Manny was a strict observer of the laws. Singapore is one of the finest places in the world for food of all sorts but only has a very modest-sized Jewish community. He would only eat food that he was certain conformed to the kashrut, the Jewish dietary laws, for example foods that had been certified by the beth din. On one visit all he could find that conformed were certain sealed tubs of Ben and Jerry's Ice Cream, so his hotel room was awash with them! On another visit, which happened to include a Saturday (Shabbat), he felt he had to move out of the modern hotel where we were staying because it only had electronic door locks, the operation of which is forbidden because it is deemed to be doing work. He managed to book into another hotel that claimed to use manual locks (perhaps the last of its kind in technology-minded Singapore) only to discover when he booked in that they had just replaced all the locks with new electric ones. I think he had to get staff at the front desk to help him each time. The Institute of Systems Sciences kindly went to a lot of trouble to honour his dietary requirements. In one occasion they arranged to take Manny and I to a wonderful Mediterranean vegetarian restaurant named Original Sin, the only one of its kind in the city-state, which among other things catered specifically for ovo lacto, vegan and even Jain customers. They felt sure they were onto a winner, but Manny felt obliged to interview the cook first and very sadly concluded that virtually all the fare on offer did not conform. Manny was a man of exceptionally strong principles, both professionally and religiously, and a wonderful arguer; I will miss him.' 'Manny used to say that his concern with the processes behind software evolution—although it was not called that then—began when in the late 1960s he told IBM software project managers, ‘you're not managing the process, the process is managing you.’ Numerous publications followed, including the initial statement in 1974, and later extensions, of the Laws of Software Evolution—Lehman's Laws. In the late 1990s Manny obtained EPSRC funding to study software evolution as a phenomenon, as he had said it needed to be. I first met Manny at my interview for a Research Associate post on this, the FEAST/1 project. For two fruitful years I and Juan Fernandez-Ramil worked with and for Manny and his long-term academic collaborators Dewayne Perry and Wlad Turski, providing evidence from in-depth industrial studies for the Laws and exploring their implications. He often expressed himself forcefully to us as we worked, but in this he demonstrated the same dedication and sense of purpose which he had applied to researching software evolution and the Laws for over twenty years before Juan and I arrived to assist him. The results of that project could not have been achieved without his vision and inspiring leadership. Recognition of the importance of his work came when the Journal of Software Maintenance was renamed the Journal of Software Maintenance and Evolution, and for him personally in the form of awards including the 2001 IEEE Harlan D. Mills Award ‘for pioneering contributions to the empirical study of software processes and program evolution’ and a banquet in his honour at the 2005 International Conference on Software Maintenance in Budapest. All this came late, which reflected the fact that the world had finally begun to catch up with him.' 'I am not sure when I first met Manny, but it must have been in the mid-80s, at least after the publication of his and Belady's book on Program Evolution (Academic Press, 1985). Manny's work on evolution has been both seminal and foundational. And a tremendous influence on my software engineering research. First, it resonated strongly with my experience as a practicing software developer and engineer. Second because it focused on what is without doubt the most critical and hardest part of a software systems life-cycle, namely where it perfects itself and adapts to new and challenging uses. The most memorable period of my time spent working with Manny (along with Wlad Turski, Warsaw University) was that in the 90s on the FEAST (Feedback, Evolution, and Software Technology) Project. It is clearly the case that there are lots of feedback loops in the software life-cycle, both formal (inspections, tests, etc) and informal. But, frustratingly, nothing even remotely resembling feedback control knobs such as you might want for turning up and down such characteristics as quality, cost, and/or time. Process improvement appears to be a step function that once taken is not reversible. All this made for lively and fascinating discussions, but often with more frustrating than satisfying results. I will miss Manny—he was a great researcher, colleague and friend.'

Web services as a new distributed system technology have been widely adopted by industries in the areas, such as enterprise application integration (EAI), business process management (BPM), and virtual organization (VO). However, lack of semantics in the current Web service standards has become a major barrier in service discovery and composition. To tackle the semantic issues of Web services, this paper proposes a comprehensive semantic service description framework - CbSSDF and a two-step service discovery mechanism based on CbSSDF-to help service users to easily locate their required services. The authors give a detailed explanation of CbSSDF, and then evaluate the framework by comparing it with OWL-S to examine how the proposed framework can improve the efficiency and effectiveness of service discovery and composition. The evaluation is carried out by analysing the different proposed solutions based on these two frameworks for achieving a series of tasks in a scenario.