Many patented goods are not sold with restrictive licences, and hence a bona fide purchaser cannot usually be prevented by the patent from doing what they like with the patented product. Indeed, the patent itself may give the reverse engineer valuable information on how the patented product operates.
However, a competitive product produced by reverse engineering may still infringe the patent itself - patent infringement does not require copying, and so "clean-room" techniques do not assist.
to go backwards. The drill in my tool box has settings marked "forward" and "reverse," but no matter which I choose, I cannot undrill a hole. Thegearshift in my car also has a position labeled R, but when I back up, the engine keeps turning in the same direction; if the car were truly reversed, it would suck in pollution through the tailpipe, converting it into gasoline and air.PRINTED CIRCUIT BOARDS (PCBS)
Computer vision has been widely used to scan PCBs for quality control and inspection purposes, and based on this, there are a number of machine vision for analysing and reverse engineering PCBs (3). Several firms on the Internet offer a service of scanning a PCB and supplying a corresponding netlist.
INTEGRATED CIRCUIT (IC) COMPONENTS
This is much harder work, since everything is on a much smaller scale.
The first step is to get through the encapsulating material into the product itself, by chemical etching or grinding. This can be tough in itself, since some manufacturers include hard particles such as carborundum or sapphire in the encapsulating the resin, so that mechanical grinding also destroys the chip.
Once at the chip surface, each layer of components is photographed, then ground away to reveal the layer below. This process reveals the structure of the chip. Again, the process can be made more difficult, for example by providing some of the components vertically across several layers.
Reverse engineering, as the name implies, is the reverse of this; in other words, the attempt to recapture the top level specification by analysing the product - "attempt" because it is not possible in practice, or even in theory, to recover everything in the original specification purely by studying the product.
Reverse engineering is difficult and time consuming, but it is getting easier all the time thanks to IT, for two reasons:
FFBDs can be developed in a series of levels. FFBDs show the same tasks identified through functional decomposition and display them in their logical, sequential relationship. For example, the entire flight mission of a spacecraft can be defined in a top level FFBD, as show
n in Figure 2. Each block in the first level diagram can then be expanded to a series of functions, as shown in the second level diagram for "perform mission operations." Note that the diagram shows both input (transfer to operational orbit) and output (transfer to space transportation system orbit), thus initiating the interface identification and control process. Each block in the second level diagram can be progressively developed into a series of functions, as shown in the third level diagram on Figure 2.[6]
These diagrams are used both to develop requirements and to identify profitable trade studies. For example, does the spacecraft antenna acquire the tracking and data relay satellite (TDRS) only when the payload data are to be transmitted, or does it track TDRS continually to allow for the reception of emergency commands or transmission of emergency data? The FFBD also incorporates alternate and contingency operations, which improve the probability of mission success. The flow diagram provides an understanding of total operation of the system, serves as a basis for development of operational and contingency procedures, and pinpoints areas where changes in operational procedures could simplify the overall system operation. In certain cases, alternate FFBDs may be used to represent various means of satisfying a particular function until data are acquired, which permits selection among the alternatives.[6]
A Functional Flow Block Diagram (FFBD) is a multi-tier, time-sequenced, step-by-step flow diagram of a system’s functional flow.[2]
The FFBD notation was developed in the 1950s, and is widely used in classical systems engineering. FFBDs are one of the classic business process modeling methodologies, along with flow charts, data flow diagrams, control flow diagrams, Gantt charts, PERT diagrams, and IDEF.[3]
FFBDs are also referred to as Functional Flow Diagrams, functional block diagrams, and functional flows.[4]
One way to understand the motivation behind systems engineering is to see it as a method, or practice, to identify and improve common rules that exist within a wide variety of systems.[citation needed] Keeping this in mind, the principles of Systems Engineering — holism, emergence, behavior, boundary, et al — can be applied to any system, complex or otherwise, provided systems thinking is employed at all levels.[18] Besides defense and aerospace, many information and technology based companies, software development firms, and industries in the field of electronics & communications require Systems engineers as part of their team[19].
An analysis by the INCOSE Systems Engineering center of excellence (SECOE) indicates that optimal effort spent on Systems Engineering is about 15-20% of the total project effort.[20] At the same time, studies have shown that Systems Engineering essentially leads to reduction in costs among other benefits.[20] However, no quantitative survey at a larger scale encompassing a wide variety of industries has been conducted until recently. Such studies are underway to determine the effectiveness and quantify the benefits of Systems engineering. [21] [22]
Systems engineering encourages the use of modeling and simulation to validate assumptions or theories on systems and the interactions within them.[23][24]
Use of methods that allow early detection of possible failures, in Safety engineering, are integrated into the design process. At the same time, decisions made at the beginning of a project whose consequences are not clearly understood can have enormous implications later in the life of a system, and it is the task of the modern systems engineer to explore these issues and make critical decisions. There is no method which guarantees that decisions made today will still be valid when a system goes into service years or decades after it is first conceived but there are techniques to support the process of systems engineering. Examples include the use of soft systems methodology, Jay Wright Forrester's System dynamics method and the Unified Modeling Language (UML), each of which are currently being explored, evaluated and developed to support the engineering decision making process.
The need for systems engineering arose with the increase in complexity of systems and projects. When speaking in this context, complexity incorporates not only engineering systems, but also the logical human organization of data. At the same time, a system can become more complex due to an increase in size as well as with an increase in the amount of data, variables, or the number of fields that are involved in the design. The International Space Station is an example of such a system.
The development of smarter control algorithms, microprocessor design, and analysis of environmental systems also come within the purview of systems engineering. Systems engineering encourages the use of tools and methods to better comprehend and manage complexity in systems. Some examples of these tools can be seen here:[16].
Taking an interdisciplinary approach to engineering systems is inherently complex since the behavior of and interaction among system components is not always immediately well defined or understood. Defining and characterizing such systems and subsystems and the interactions among them is one of the goals of systems engineering. In doing so, the gap that exists between informal requirements from users, operators, marketing organizations, and technical specifications is successfully bridged.
System development often requires contribution from diverse technical disciplines.[13] By providing a systems (holistic) view of the development effort, systems engineering helps meld all the technical contributors into a unified team effort, forming a structured development process that proceeds from concept to production to operation and, in some cases, to termination and disposal.
This perspective is often replicated in educational programs in that Systems Engineering courses are taught by faculty from other engineering departments which, in effect, helps create an interdisciplinary environment[14][15].
Systems Engineering signifies both an approach and, more recently, as a discipline in engineering. The aim of education in Systems Engineering is to simply formalize the approach and in doing so, identify new methods and research opportunities similar to the way it occurs in other fields of engineering. As an approach, Systems Engineering is holistic and interdisciplinary in flavor.
Systems Engineering focuses on defining customer needs and required functionality early in the development cycle, documenting requirements, then proceeding with design synthesis and system validation while considering the complete problem, the system lifecycle. Oliver et al. claim that the systems engineering process can be decomposed into
Within Oliver's model, the goal of the Management Process is to organize the technical effort in the lifecycle, while the Technical Process includes assessing available information, defining effectiveness measures, to create a behavior model, create a structure model, perform trade-off analysis, and create sequential build & test plan[11].
Depending on their application, although there are several models that are used in the industry, all of them aim to identify the relation between the various stages mentioned above and incorporate feedback. Examples of such models include the Waterfall model and the VEE model[12]The movement traces its roots to the ideas expressed in written works. The Pragmatic Programmer by Andy Hunt and Dave Thomas and Software Craftsmanship by Pete McBreen explicitly position software development as heir to the guild traditions of medieval Europe. The philosopher Richard Sennet wrote about software as a modern craft in his book The Craftsman. Freeman Dyson, in his essay "Science as a Craft Industry", expands software crafts to include mastery of using software as a driver for economic benefit:
The most important task in creating a software product is extracting the requirements or requirements analysis. Customers typically have an abstract idea of what they want as an end result, but not what software should do. Incomplete, ambiguous, or even contradictory requirements are recognized by skilled and experienced software engineers at this point. Frequently demonstrating live code may help reduce the risk that the requirements are incorrect.
Once the general requirements are gleaned from the client, an analysis of the scope of the development should be determined and clearly stated. This is often called a scope document. Certain functionality may be out of scope of the project as a function of cost or as a result of unclear requirements at the start of development. If the development is done externally, this document can be considered a legal document so that if there are ever disputes, any ambiguity of what was promised to the client can be clarified.
Domain Analysis is often the first step in attempting to design a new piece of software, whether it be an addition to an existing software, a new application, a new subsystem or a whole new system. Assuming that the developers (including the analysts) are not sufficiently knowledgeable in the subject area of the new software, the first task is to investigate the so-called "domain" of the software. The more knowledgeable they are about the domain already, the less work required. Another objective of this work is to make the analysts, who will later try to elicit and gather the requirements from the area experts, speak with them in the domain's own terminology, facilitating a better understanding of what is being said by these experts. If the analyst does not use the proper terminology it is likely that they will not be taken seriously, thus this phase is an important prelude to extracting and gathering the requirements. If an analyst hasn't done the appropriate work confusion may ensue: "I know you believe you understood what you think I said, but I am not sure you realize what you heard is not what I meant."[1]
Specification is the task of precisely describing the software to be written, possibly in a rigorous way. In practice, most successful specifications are written to understand and fine-tune applications that were already well-developed, although safety-critical software systems are often carefully specified prior to application development. Specifications are most important for external interfaces that must remain stable. A good way to determine whether the specifications are sufficiently precise is to have a third party review the documents making sure that the requirements and Use Cases are logically sound.
The architecture of a software system or software architecture refers to an abstract representation of that system. Architecture is concerned with making sure the software system will meet the requirements of the product, as well as ensuring that future requirements can be addressed. The architecture step also addresses interfaces between the software system and other software products, as well as the underlying hardware or the host operating system.
Implementation is the part of the process where software engineers actually program the code for the project.
Software testing is an integral and important part of the software development process. This part of the process ensures that bugs are recognized as early as possible.
Documenting the internal design of software for the purpose of future maintenance and enhancement is done throughout development. This may also include the authoring of an API, be it external or internal.
Deployment starts after the code is appropriately tested, is approved for release and sold or otherwise distributed into a production environment.
Software Training and Support is important because a large percentage of software projects fail because the developers fail to realize that it doesn't matter how much time and planning a development team puts into creating software if nobody in an organization ends up using it. People are often resistant to change and avoid venturing into an unfamiliar area, so as a part of the deployment phase, it is very important to have training classes for new clients of your software.
Maintenance and enhancing software to cope with newly discovered problems or new requirements can take far more time than the initial development of the software. It may be necessary to add code that does not fit the original design to correct an unforeseen problem or it may be that a customer is requesting more functionality and code can be added to accommodate their requests. It is during this phase that customer calls come in and you see whether your testing was extensive enough to uncover the problems before customers do.
Professional certification of software engineers is a contentious issue. Some see it as a tool to improve professional practice; "The only purpose of licensing software engineers is to protect the public" [13]
The ACM had a professional certification program in the early 1980s,[citation needed] which was discontinued due to lack of interest. The ACM examined the possibility of professional certification of software engineers in the late 1990s, but eventually decided that such certification was inappropriate for the professional industrial practice of software engineering.[14] As of 2006[update], the IEEE had certified over 575 software professionals.[15] In Canada the Canadian Information Processing Society has developed a legally recognized professional certification called Information Systems Professional (ISP)[16]. The Software Engineering Institute offers certification on specific topic such as Security, Process improvement and Software architecture[17].
Most certification programs in the IT industry are oriented toward specific technologies, and are managed by the vendors of these technologies.[18] These certification programs are tailored to the institutions that would employ people who use these technologies.
Software engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software.[1]
The term software engineering first appeared in the 1968 NATO Software Engineering Conference and was meant to provoke thought regarding the current "software crisis" at the time.[2] Since then, it has continued as a profession and field of study dedicated to creating software that is of higher quality, cheaper, maintainable, and quicker to build. Since the field is still relatively young compared to its sister fields of engineering, there is still much work and debate around what software engineering actually is, and if it deserves the title engineering. It has grown organically out of the limitations of viewing software as just programming. Software development is a term sometimes preferred by practitioners in the industry who view software engineering as too heavy-handed and constrictive to the malleable process of creating software.
Yet, in spite of its youth as a profession, the field's future looks bright as Money Magazine and Salary.com rated software engineering as the best job in America in 2006.Software blueprinting processes advocate containing inspirational activity (problem solving) as much as possible to the early stages of a project in the same way that the construction blueprint captures the inspirational activity of the construction architect. Following the blueprinting phase only procedural activity (following prescribed steps) is required. This means that a software blueprint must be prescriptive and therefore exhibit the same formality as other prescriptive languages such as C++ or Java. Software blueprinting exponents claim that this provides the following advantages over enduring inspiration:
Software blueprints focus on one aspect to avoid becoming diluted by compromising choice of description medium and to ensure that all of the relevant logic is localized.
The single aspect focus of a software blueprint means that the optimal description medium can be selected. For example, algorithmic code may be best represented using textual code whereas GUI appearance may be best represented using a form design.
The motivation behind selecting an intuitive description medium (i.e. one that matches well with mental models and designs for a particular aspect) is to improve:
The localization of aspect logic promoted by the software blueprinting approach is intended to improve navigability and this is based on the assumption that the application programmer most commonly wishes to browse application aspects independently.
Software blueprinting relies on realizing a clean separation between logically orthogonal aspects to facilitate the localization of related logic and use of optimal description media described above.
The GUI form design (see GUI toolkit) is widely adopted across the software industry and allows the programmer to specify a prescriptive description of the appearance of GUI widgets within a window. This description can be translated directly to the code that draws the GUI (because it is prescriptive).
Languages such as the Concurrent Description Language (CDL) separate an application's macroscopic logic (communication, synchronization and arbitration) from complex multi-threaded and/or multi-process applications into a single contiguous visual representation. The prescriptive nature of this description means that it can be machine translated into an executable framework that may be tested for structural integrity (detection of race conditions, deadlocks etc.) before the microscopic logic is available.
Class designers allow the specification of arbitrarily complex data structures in a convenient form and the prescriptive nature of this description allows generation of executable code to perform list management, format translation, endian swapping and so on.
Classes are used as building blocks by software designers to model more complex structures. In software architecture the Unified Modeling Language (UML) is an industry standard used for modeling the blueprint of software. UML represents structure, associations and interactions between various software elements, like classes, objects or components. It helps the software designer to design, analyze and communicate ideas to other members of the software community.
A comprehensive Web site has been developed to complement the content of the SEPA, 6/e. The Web site, called SepaWeb, provides a broad array of software engineering resources that will benefit instructors, students, and industry professionals.
Like all Web sites, SepaWeb will evolve over time, but the following major content areas will always be present:
(1) a broad array of instructor resources including a comprehensive on-line Instructor's Guide and supplementary teaching materials (e.g., slide presentations to supplement lectures);In addition, SepaWeb will contain other goodies that are currently in development.
(2) a wide variety of student resources including an extensive on-line learning center (encompassing study guides, problem solutions, web-based resources, a FAQ for each chapter, and self-tests), an evolving collection of "tiny tools," a case study, and additional supplementary content, and
(3) a detailed collection of professional resources including outlines (and samples of) software engineering documents and other work products, a useful set of software engineering checklists, a catalog of software engineering (CASE) tools, a comprehensive collection of web-based resources, and an "adaptable process model" that provides a detailed task breakdown of the software engineering process.
A software developer is a person or organization concerned with facets of the software development process wider than design and coding, a somewhat broader scope of computer programming or a specialty of project managing including some aspects of software product management. This person may contribute to the overview of the project on the application level rather than component level or individual programming tasks. Software developers are often still guided by lead programmers but also encompasses the class of freelance software developers.
Other names which are often used in the same close context are software analyst and software engineer.
With time and a little luck, differences between system design, software development and programming are more apparent. Already in the current market place there can be found a segregation between programmers and developers, being that one who actually implements is not the same as the one who designs the class structure or hierarchy. Even more so that developers become systems architects, those who design the multi-leveled architecture or component interactions of a large software system.[1] (see also Debate over who is a software engineer)
A 'programmer' is responsible for writing code,[1] but a 'developer' could be involved in wider aspects of the software development process such as:
In a large company there may be employees whose sole responsibility may consist of only one of the phases above. In smaller development environments, a few, or even a single individual might handle the complete process.
The process of manufacturing software systems. A software system consists of executable computer code and the supporting documents needed to manufacture, use, and maintain the code. For example, a word processing system consists of an executable program (the word processor), user manuals, and the documents, such as requirements and designs, needed to produce the executable program and manuals. See also Software engineering.
Software engineering is ever more important as larger, more complex, and life-critical software systems proliferate. The rapid decline in the costs of computer hardware means that the software in a typical system often costs more than the hardware it runs on. Large software systems may be the most complex things ever built. This places great demands on the software engineering process, which must be disciplined and controlled.
The January issue of SEN includes reports and papers on:
The letters and columns in the January issue include the following:
