Software engineering principles

Software engineering principles Chapter 1 Software is a great combination between artistry and engineering. When you finally get done and get to appreciate what you have done it is like a part of yourself that youve put together. I think a lot of the people here feel that way. Introduction This report discusses Software Engineering principles in context with Service-Oriented applications. Software Engineering covers a very vast area. It encourages the development of high quality and sustainable software,using quality software engineering tools and techniques. Service Orientation on the other hand is a trend in Software Engineering, its an approach, a way of thinking, a value system that promotes the construction of applications based on activities called services. It was very complicated to conclude the basic principles of Software Engineering and then to make a decision which of these principles are applicable and which are not applicable to the development of Service Oriented Applications. There exists so much information on Software Engineering and Service-Oriented applications but very few talks about the Software Engineering principles and their relation with SOA. However, after browsing through the internet and digging into many Software Engineering and SOA books and journals some conclusion is made which is described in detail in following pages. Like most of the researches, this research also takes into consideration few assumptions which are stated clearly. Chapter 2 In order to be acquainted with the principles of Software Engineering it is essential to have a brief idea about it. The paragraph below will assist in giving some idea about Software Engineering. About Software Engineering. As mentioned above Software Engineering covers a very huge part in a development of any software. It is not a complex approach but over the years everyone has presented a different definition for Software Engineering because of its diversity. To get the more precise and clear picture, a few definitions from different sources are presented below. The establishment and use of sound engineering principles (methods) in order to obtain economically software that is reliable and works on real machines [Bauer 1972]. Software engineering is that form of engineering that applies the principles of computer science and mathematics to achieving cost-effective solutions to software problems. [CMU/SEI-90-TR-003] The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software [IEEE 1990]. There are aspects of each of these definitions that have a say to the viewpoint of software engineering used in the construction of this report. One particularly important aspect is that software engineering builds on computer science and mathematics. Software engineering encompasses a process, the management of activities, technical methods, and use of tools to develop high-quality, systematic, controlled, and efficient software products. Software is engineered by applying three discrete phases definition, development, and support. Subsequently, there are significant emphasis on analysis and evaluation, specification, design, and evolution of software. In accumulation, there are issues related to management and quality, to novelty and creativity, to standards, to individual skills, and to teamwork and professional practice that play a vital role in software engineering. Chapter 3 Service Orientation is a trend in software engineering that promotes the construction of application based on entities called services [9]. Service-Oriented Architecture A service-oriented architecture is the organizational and technical framework that enables an enterprise to deliver self-describing, platform-independent business functionality and make it available as building blocks of current and future applications. Simply speaking, in an SOA, a business is viewed as a portfolio of services that can be delivered independently and recombined without requiring detailed knowledge of how that service is implemented. [8] According to Wikipedia, incomputing,service-oriented architecture(SOA) has different non-standard and openly-debated definitions. Basically, it is an attempt to provide set of principles or governing concepts used during phases ofsystems developmentandintegration. Such architecture is supposed to package functionality asinteroperableservices within the context of variousbusiness domainsinvolved. Several departments within a company or different organizations may integrate or use such services à ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬ software modules provided as a service à ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬ even if their respectiveclientsystems are substantially different. It is an attempt to develop yet another means for software module integration. Rather than defining anAPI, SOA defines the interface in terms of protocols and functionality. Anendpointis the entry point to such an SOA implementation. Chapter 4 Principles of Software Engineering A set of fundamental principles can act as an enabler in the establishment of a discipline; however, software engineering still lacks a set of universally recognized fundamental principles. A fundamental principle is less specific and more enduring than methodologies and techniques. It should be phrased to withstand the test of time. It should not contradict a more general engineering principle and should have some correspondence with best practice. It should be precise enough to be capable of support and contradiction and should not conceal a trade off. It should also relate to one or more computer science or engineering concepts. [1] Principles are common and conceptual statements describing desirable properties of software products and processes. Principles become practice through methods and techniques, often methods and techniques are packaged in a methodology. Methodologies can be enforced by tools. Principles of Software Engineering have a good impact on the process of software engineering and also on the final product. These principles facilitate to develop software in such a manner that it posses all the qualities like: efficiency, functionality, adaptability, maintainability, and usability. Principles are general, abstract statements describing desirable properties of software processes and products. The principles are applicable throughout the lifecycle of the software. Principles are the set of statements which describe the advantageous features of the product and process. Focus on both process and product is needed to deliver software systems. These principles help in controlling process which in turn helps to control the quality of the product. Only the control of process will not guarantee a quality product therefore it is important to concentrate on both process and quality. As said earlier there are no fundamentally recognized principles of Software Engineering but we can list down few that may be used in all phases of software development. Rigor and formality Separation of concerns Modularity and decomposition Abstraction Anticipation of change Generality Incremental Development Reliability Principles explained. Rigor and formality Webster defines Rigor as. harsh inflexibility in opinion, temper, or judgment : severity the quality of being unyielding or inflexible : strictness severity of life : austerity b: an act or instance of strictness, severity, or cruelty 2: a tremor caused by a chill 3: a condition that makes life difficult, challenging, or uncomfortable; especially : extremity of cold strict precision : exactness Webster defines Rigor as harsh inflexibility in opinion, but thats not the general meaning of rigor in project management. In general Rigor means the strict precision with which you follow some project management belief or practice. Advancements of this approach enable us to construct more consistent product, organize their cost, and boost our confidence in their reliability. Formality is a stronger requisite than rigor; it requires the software process to be driven and evaluated by mathematical laws. As it is seen that Software engineering is a very imaginative design activity, so it must be practiced systematically. Rigor is an essential match to imagination that increases our confidence in our developments. Formality is rigor at the highest degree. Software development can accept neither ambiguity nor inaccuracy. Where rigidness helps to produce consistent products, controlling cost and increases discretion in products, Formality checks the process of software production using mathematical laws. Rigor and formality in context with SOA SOA aims to improve flexibility. The key reason for using SOA is that it should help you in your business. For example, you may need IT solutions that store and manage your data, and allow you to automate the usual processes that deal with this data. A critical factor for business success these days is keeping time to market share. To deliver a quality solution right on time, you need flexibility. But flexibility has a lot to do with clear organization, roles, processes, and so on. Therefore, SOA has to deal with all these aspects. [10] Conclusion For Software Engineering, Rigor means the strict precision with which you follow some project management belief or practice. On the other hand SOA follows agile methodology which can be described as iterative and incremental. As SOA is intended to enable flexibility, adaptability and reusability, this principle is not applicable to SOA. Separation of concerns There is a very popular saying Divide and conquer, it holds good in software development process also. This principle teaches to first divide or break the problem into small and different modules. This helps in dealing with different individual aspects of a problem and we can concentrate on each part separately. A problem can be divided with respect to time, quality, complexity etc. Once the problem is divided into pieces a project leader can thus easily separate the responsibilities among the developers. By doing this development of a big part of the project can be done in parallel, thus saving time. Separation of concerns in context with SOA SOA is all about services. SOA is nothing without services. Services are primary assets of SOA. Services in SOA are modules of business or application functionality with exposed interfaces that are invoked by messages from service consumers. [11]. Conclusion In SOA, complex problems are divided into different modules to design various reusable and interoperable services. Thus this principle does applicable to SOA. Modularity and decomposition Modularity is a kind of Separation of concerns. A complex problem can be divided into simpler parts called modules, allowing details of each module being handled in isolation and separately. A system that is collected of modules is called modular. When dealing with different modules we can ignore details of some not so important modules. Each separated module should be highly interconnected with the rest of the modules so that each module should be understandable as a meaningful unit. Components of a each module should be closely related to one another. Modules should exhibit low coupling means they should have low interactions with other modules. Too much interaction with other modules makes a module dependent on other, thus making it less reusable. Modularity in context with SOA Service contracts impose low consumer coupling requirements and are themselves decoupled from their surrounding environment. [12] Conclusion Loose Coupling is one of the basic principles of SOA. The principle of Service Loose Coupling promotes the independent design and evolution of a services logic and implementation while still guaranteeing baseline interoperability with consumers that have come to rely on the services capabilities [12]. This principle does applicable to SOA. Abstraction A software developer cannot deal with more than a few concepts and their relationships simultaneously. An abstraction allows suppressing details that are unimportant to him/her and emphasize the important information [2]. Abstraction helps manage the intellectual complexity of software [3]. Abstracting means that a higher-level concept disregards certain properties altogether [4, 5]. Abstraction is also related to Separation of Concerns. Here the modules are separated on the basis of purpose of the module. Actually we separate what from how. Then we can easily make out the central aspects of a phenomenon and overlook its details. Abstraction is the only tool through which we can actually master the complexity of the problem. Abstraction depends on the functionality of the module (What) or point of view. To decide which type of abstraction is to apply mainly depends on the purpose of the particular problem. Abstraction in context with SOA Service contracts only contain essential information and information about services is limited to what is published in service contracts. [12] Conclusion Abstraction ties into many aspects of service-orientation. On a fundamental level, this principle emphasizes the need to hide as much of the underlying details of a service as possible. Doing so directly enables and preserves the previously described loosely coupled relationship. Service Abstraction also plays a significant role in the positioning and design of service compositions. [12]. This principle does applicable to SOA. Anticipation of change The only constant is change. Change is everywhere. Even in Software development change always happens. It is very important to identify any likely change in the early phase of software development. When expected changes are recognized, a particular care must be taken to progress in a way that will make future changes easy to apply. The changes occur because usually the entire software requirement is not understood by the development team and this happens because of the communication gap between client and software team. Also most of the times the users and the environment of the requirement changes which leads to the minor and some time even major changes in the application. Such major changes affect the supervision of the software process. A small change in the application pushes the finished product back into the software development life cycle. It becomes necessary to do a regression testing with maintenance. Maintenance is the process where modifications are done to the application to reflect the changing requirements. Anticipation of change in context with SOA Conclusion Generality Generality can be characterized as a state or quality of being not limited to one particular case. Generalisation, as an inductive process, collects information about a number of particulars and presents it in a single description [6]. General description collects a set of individuals according to the features that are applicable to the whole as well as to every member of a set. As noted in Navrat [5], generalisation moves things along the set-superset relation. Specialization, as an opposite operation, moves things in set-subset relation. Less general description determines a smaller set of things, while its transformation to a more general description will determine a superset of the original set. Every member of less general set is a member of more general superset. While breaking a big problem into small modules one should generalize the problem to make the solution more potential for being reused. But a careful balance between performance and cost is necessary while generalizing a problem. Generalization often helps in solving some special case easily. Incremental Development Keep developing until you get it right. Incremental development is based on agile methodology. Agile methods generally promote a disciplined project management process that encourages frequent inspection and adaptation, a leadership philosophy that encourages teamwork, self-organization and accountability, a set of engineering best practices that allow for rapid delivery of high-quality software, and a business approach that aligns development with customer needs and company goals. [7] Incremental development means development in a stepwise fashion. According to this principle a subset of the system is delivered early to get the feedback from the users in the early stages of the development. New features or changes , if any, can thus be added incrementally during the early stages without doing much of changes in the structure of the system. It focuses first, more on the functionality, then turn to performance. It is a step-wise process which makes closer approximations to reach a desired goal. But a closer and careful management interference and documentation is necessary during all the steps. Incremental Development in context with SOA. As stated earlier, SOA is based on agile methodology. A disciplined Agile software development definition can be An iterative and incremental (evolutionary) approach to software development which is performed in a highly collaborative manner by self-organizing teams within an effective governance framework with just enough ceremony that produces high quality software in a cost effective and timely mannerwhich meets the changing needs of its stakeholders. [13] Conclusion Reliability According to ANSI, Software Reliability is defined as: the probability of failure-free software operation for a specified period of time in a specified environment.[ANSI91][Lyu95]. The NASA Software Assurance Standard, NASA-STD-8739.8, defines software reliability as a discipline of software assurance that: Defines the requirements for software controlled system fault/failure detection, isolation, and recovery; Reviews the software development processes and products for software error prevention and/or reduced functionality states; and, Defines the process for measuring and analyzing defects and defines/derives the reliability and maintainability factors. Reliability in context of SOA For services to carry out their capabilities consistently and reliably, their underlying solution logic needs to have a significant degree of control over its environment and resources. The principle of Service Autonomy supports the extent to which other design principles can be effectively realized in real world production environments by fostering design characteristics that increase a services reliability and behavioural predictability. [12] Conclusion Principle of Autonomy is one of the principles of SOA which talks about the reliability and behavioural predictability. This principle does applicable to SOA. References Abstracts from Fundamentals of Software Engineering, Second Edition, by Carlo Ghezzi, Mehdi Jazayeri, and Dino Mandrioli. Krueger, Ch. W., 1992. Software Reuse. ACM Computing Surveys, 24: 131-83. Pree, W., 1994. Design Patterns for Object-Oriented Software Development. Addison-Wesley. NÃÆ' ¡vrat, P., 1994. Hierarchies of programming concepts. Abstraction, generality and beyond. ACM SIGCSE Bulletin, 26: 17-21, 28. NÃÆ' ¡vrat, P., 1996. A Closer Look at Programming Expertise. Critical Survey of Some Methodological Issues. Information and Software Technol., 1: 37-46. Czarnecki, K. and U.W. Eisenecker, 2000. Generative Programming. Methods, Tools and Application. Addison Wesley. From Wikipedia, the free encyclopedia. Cartwright and Doernenburg 48 (3): 26. (2006) Zoran Stojanovic Ajantha Dahanayake. Service-Oriented Software System Engineering, Challenges and Practices. 1 Nicolai. M. Josuttis, 2007. SOA in practice. The art of distributed system design. 12-13. Eric A. Marks Michael Bell, 2006. Service-Oriented Architecture, A Planning and Implementation Guide for Business and Technology. 33-34 http://www.soaprinciples.com SOA: Principles of Service Design, byThomas Erl http://www.agilemodeling.com/essays/agileSoftwareDevelopment.htm http://www.agilemodeling.com/essays/agileSoftwareDevelopment.htm http://www.soaprinciples.com/service_autonomy.asp

Karl Marx and Old Major

Karl Marx believed that the policies of the government should be controlled by the lowest working class rather than the upper middle class. â€Å"The first step on the path to the workers' revolution is the elevation of the proletariat to the position of ruling class (â€Å"Dictatorship of the Proletariat†). † As the animals was the labor community of the farm they should command, â€Å"getting rid of Man, and the produce of our labor would be our own (Orwell 7). † Just like Karl Marx, Old Major also believe that a community should be ruled by those who work for it, not the upper middle class.The power concentrated in the hands of the minority was getting in the way of the development of communism. â€Å"The theory of communism may be summed up in one sentence: abolish all private property (â€Å"Chapter II. Proletarians and Communists†). † Their lives was simple, â€Å"The animals were born and given just so much food as will keep the breath in ou r bodies, and those who are capable of it are forced to work to the last atom of their strength (Orwell 6). The majority works on behalf of a minority, this small piece grows while the overall decays, the labor of the animals it isn't in their favor, Mr. Jones takes advantages of them just like the capitalism system. In a socialist society, everyone would receive an equal amount of goods. In Critique of the Gotha Programme, Karl Marx said â€Å"From each, according to his ability, to each, according to his need (â€Å"Critique of the Gotha Programme†).Manor farm would support a dozen horses, twenty cows, hundreds of sheep- and all of them living in a comfort and a dignity that are now almost beyond their imagination (Orwell 7). † In the farm, the animals were underfeed in a land where everybody could eat properly as Marx and Old Major believes every goods should be equally divided. Karl Marx wanted the equality between the proletariat and the bourgeoisie. Rachel McHenr y wrote about his theories, â€Å"It was also Marx's belief that before complete equality could take place there must be a dominance of the proletariats.The dictatorship of the former lower class will last for a short while, this being necessary for order's sake. (â€Å"Encountering Communism: The Theories of Karl Marx†). † Man serves the interest of no creature except himself, no one should be submissive to another. And among the animals let there be perfect unity (Orwell 10)† In Animal farm, Karl Marx ideas are mirrored by Old Major ideas, the union of the lower classes is the power of change.

The True Story About Academic Essay Samples That the Experts Dont Want You to Hear

The True Story About Academic Essay Samples That the Experts Don't Want You to Hear The Nuiances of Academic Essay Samples Standard introduction paragraphs have a unique function. A superb balance of simple and elaborate sentences is utilised to develop an argument. Essay content and emphasis starts to differ based on the demands of the subject and the intention behind the essay, and there are recognizable patterns for ordering paragraphs that we are able to pick out for assorted purposes. The previous sentence provides the reply to the essay question. Reflective essays serve only a single purpose to reveal your capacity to logically reflect on a specific issue. The course materials that you have to speak about within an academic essay can reflect your degree of understanding about the topic. Jectivity is an element that has to be constantly present when writing an academic paper. Be precise with the aim of your writing. You may use the samples as a foundation for working out how to write in the appropriate style. When you are requested to compose an essay, attempt to discover some samples (models) of. All the reference items begin with the title of the information supply. Use certain reasons and examples to back up your answer. It's because academic essays must be painstakingly meticulous that men and women in the academy will sometimes say, an essay isn't a statement of opinion. Don't hold yourself back if you think that you are prepared to compose a specific section of the essay. Therefore don't get intimidated if you believe you cannot write such essays. Informative essays should supply the reader with data on the essay topic you have chosen. There are additional elements which you also will need to take into account when writing your academic essay. The most important point to be cautious about in personal descriptive essay is that there shouldn't be any over-exaggeration. These IELTS sample essays are categorised in a manner that makes it simple for you to observe how certain essay question types ask that you give certain responses to be sure the question is totally answered. If you wish to make an academic essay that's both outstanding and relevant, always place the items that we've discussed above in mind. Within this section you will locate samples of essays belonging to several essay types and manners of formatting. When you are requested to compose an essay, attempt to locate some samples (models) of similar writing and learn how to observe the craft of the writer. If you're to really gain from model essays, you will need to understand how to read the techniques of the writer'. Our sample essay has a straightforward but great introduction in which it demonstrates that the examinee has knowledge of the subject and clearly states the writer's position to prepare the remainder of the essay. Where to Find Academic Essay Samples Writing a significant academic composition for school is regarded as a challenge for many students owing to its seriousness and technical austerity. Expert tips to boost your college writing. Our talented writers can deal with nearly every form of writing assignment, together with Math and Physics difficulties and a whole lot more. Choosing online man writ ers isn't a homophile anymore. Descriptive Essay on Market can be employed by tourists or visitors that don't have any prior understanding of a marketplace. People today attend college or university for many diverse reasons (for instance, new experiences, career preparation, or to raise knowledge). Both law and company schools also often need several essays of their applicants, with questions which range from details about your private background to questions asking you to compose an essay exploring a controversial matter. In that instance it is known as a college admission essay. The more you tell us about your requirements, the better essay help we'll be in a position to provide. There are someA last minute essay writingA activities that are finished in many fields especially if students believe an academic essay is merely part of their requirements. There aren't any dates of publication in all the references. If you take a close look at descriptive essays from a different perspective, you will see them very much like everyday news reports. When utilizing a template for a guide, always make sure it's applicable to the study that you're practicing or the academic area or discipline at which you will use your academic essay. In the middle of your research procedure, the info you've gathered can help you formulate superior ideas on what you have to say in the essay.

Richard Swinburnes Teleological Argument - 790 Words

Richard Swinburnes Teleological Argument Although explicated on many occasions and by many different authors, the teleological argument for the existence of God provides the best springboard from which to launch contemporary convictions of faith. In the revised edition of his earlier The Existence of God, Richard Swinburne constructs a solid outline that reveals the exact structure of the teleological argument. He presents both forms of the teleological argument , holds each under the light of skeptical review and then provides insight and defense that allows for careful philosophical review. Swinburne begins his outline of the teleological argument by identifying its two forms: regularities of co-presence and regularities†¦show more content†¦By natural processes they can only come into being through generation. But we know that the world has not been going on forever, and so the great puzzle is the existence of the first animals and plants in 4004 BC or whenever exactly it was that animals and plants began to exist. Since they could not have come about by natural scientific processes, and since they are very similar to the machines, which certain rational agents, viz. men, make, it is very probable that they were made by a rational agent -- only clearly one more powerful and knowledgeable than men. According to this version of the teleological argument, that entity more powerful and knowledgeable than man is God. The teleological argument whose version identifies regularities of co-presence is quickly dismantled with the introduction of Mr. Charles Darwin. Complex animals and plants, Swinburne argues, can be produced through generation by less complex animals and plants -- species are not eternally extinct; and simple animals and plants can be produced by natural processes from inorganic matter. And in this simple language the logical validity of regularities of co-presence simply ceases to exist: something of a philosophical evolution. And like the very argument that dismantled regularities of co-presence, Swinburnes argument evolves into a more complex version identified by regularities of succession. Regularities of succession,Show MoreRelatedThe Design Argument - as Level Essay examples3128 Words   |  13 Pagesa. Outline the Key Concepts of the Design Argument [21 marks] The design argument is also referred to at the Teleological Argument stemmed from the Greek work ‘Telos’ meaning end or purpose. It is an ‘A posterior’ argument (from experience) based on our empirical senses and it is synthetic meaning that it is from observation. The argument is also inductive meaning there a number of possible conclusions. The main basis of the Teleological argument is based on a designer commonly known as ‘theRead MoreThis essay will be examining the key arguments for the existence of God, in order to discuss the3100 Words   |  13 PagesThis essay will be examining the key arguments for the existence of God, in order to discuss the claim that â€Å"it is wrong to believe in anything without sufficient evidence†- with reference to the non-existence of God. It will be exploring both a priori and an a posteriori argument for the existence of God. It will solely be concentrating on the Theological argument, Cosmological argu ment and the Ontological argument, in order, to analyse their significance and contribution in vindicating the claimRead MoreReligious Experiences are in the Mind of the Believer Essays2837 Words   |  12 Pageswere a trick of the mind it would only last a few seconds at the most. Therefore this is evidence against the quote and as a result strengthens and provides evidence for the existence of religious experiences. Nonetheless, Richard M. Gale disagrees that mystical experiences should be thought of as ineffable in some way in which other experiences are not. Instead, he believes that mystical experiences are â€Å"if ineffable, ineffable in just the way that