— CS302: Software Engineering —
Software engineering is a discipline that allows us to apply engineering and computer science concepts in the development and maintenance of reliable, usable, and dependable software. The concept of software engineering was first discussed at the 1968 NATO Science Committee in Germany. Today, many practitioners still debate over the term software engineering, often arguing that this discipline does not meet the criteria of engineering; rather, it should be called software development. There are several areas to focus on within software engineering, such as design, development, testing, maintenance, and management. Software development outside of the classroom is a very complex process, mostly because real-world software is much larger and more complex.
The purpose of this course is to present software engineering as a body of knowledge. The course is designed to present software engineering concepts and principles in parallel with the software development life cycle. The course will begin with an introduction to software engineering, giving you a definition of this body of knowledge, as well as a discussion of the main methodologies of software engineering. You will then learn about the Software Development Life Cycle (SDLC) followed by software modeling using Unified Modeling Language (UML), a standardized general-purpose modeling language used to create visual models of object-oriented software. You will go on to learn about five major phases of the SDLC: requirements gathering, requirements analysis, design, coding/implementation, and testing. You will also learn about project management for the purpose of delivering high-quality software that satisfies customer needs and is within budget.
By the time the course is complete, you will master software engineering concepts, principles, and essential processes of the SDLC; you will demonstrate this knowledge by creating UML artifacts for requirements gathering, analysis as well as design phases using an object-oriented methodology.
When dependency on software and computers became more important, software grew in size and became a necessity for businesses and users all over the world. In the last 30 years, we have seen an unparalleled explosion in the amount of software produced and used by our modern society. There is now a need to set concrete objectives (e.g. functional requirements), predict necessary resources (e.g. cost estimates) to attain those objectives, and manage customers' expectations.
As you review the material in this unit, compare and contrast software engineering with computer science. These two disciplines are closely related, but they have some differences. It is important to gain this understanding as you review the material in subunit 220.127.116.11. Also, spend some time on the three commonly used methodologies in software engineering (i.e., data-oriented, process-oriented and object-oriented). You will find this central theme (i.e. the three methodologies) repeated in software requirements and analysis as well as software design.
Software development life cycle (SDLC) refers to the process of software development. The International Organization for Standardization's ISO12207, the industry standard for software life cycle processes, describes the development process as consisting of requirements, design, code, and (three levels of) testing. There are different approaches to break down the work when developing software systems. Waterfall, v-shape, prototype, incremental, spiral, etc. are examples of SDLC models. Conceptually, each model provides specific guidance to the sequencing and repetition of life cycle activities to deliver high-quality software systems. The various life cycle models fall into two basic categories: sequential and iterative.
As you review the material in this unit, try to see the similarities in these two categories of life cycle models from the ISO12207 development process perspective (i.e., requirements, design, code, and testing). This will help you grasp the basic concepts of SDLC. This unit connects strongly with Unit 9: Project Management. Choosing and managing a software life cycle process is a central component of project management.
Many believe that good design is fundamental to creating successful software. The first step in software creation is to gather requirements.Notations, such as UML, allow us to articulate complex ideas succinctly and precisely. Designing software requires the use of certain industry standard design tools, and mastery of them is essential to becoming a capable software engineer.
This unit will introduce you to UML, a standardized general-purpose modeling language for creating visual models of object-oriented software. This unit aims to give you a comprehensive understanding of UML, the five fundamental artifacts of UML, and modeling concepts, as well as the modeling concepts' relationships to the terms system, model, and view.
Requirements gathering requires the software engineer (in this case, a business analyst) to interact with the stakeholders, including customer and users,to gather/collect information about what the software system being developed needs to do. There is also the situation where vendors are subcontracted to develop all, or some components, of the software systems and/or develop the hardware that the software will run on. In this case, the vendors bid on the subcontract by providing a proposal in responds to a request for proposals. In this unit, you will learn the data/information types, data collection techniques, and data collection and application types. This unit will set the stage for the next two units: Unit 5: Software Requirements Analysis, and Unit 6: Software Design.
Requirements elicitation requires the software engineer to interact with the stakeholder including customer users,to gather information about what the software system needs to do. In this unit, we examine the software engineer's activities to elicit, to analyze (or translate), to validate and to manage this phase of the life cycle in working with the customer to achieve a common understanding of the customer's goals. This set of activities is referred to as analysis and focuses on what the application will do, whereas design describes how the application will work (Unit 6: Software Design). There are many ways to elicit and analyze customer requirements. As introduced in subunit 1.2, the three most commonly used methodologies are data-oriented, process-oriented, and object-oriented. In this unit, we will drive deeper and examine the conceptual foundations, activities, and deliverables underlying each of these methodologies applicable to software requirements and analysis.
As you review the material in this unit, spend some time on the object-oriented methodology as it applies to software requirements and analysis. You will be applying this in a later unit to put it all together in a case study.
After requirements and analysis, a software engineer must transform the analysis model into a design model that can be implemented in a specific hardware and software environment. In this unit, we will discuss the principles of design and architecture design. Just as there are various methodologies for requirements analysis, we will drill down from the analysis model(s) to the design model(s) following the three corresponding methodologies (i.e., data-oriented, process-oriented, and object-oriented).
As you review the material in this unit, spend some time on the object-oriented methodology as it applies to software design. You will be applying this in a later unit to put it all together in a case study.
Implementation, also known as programming or coding, is the process of using a programming language to convert specified requirements into software source code and later into compiled code for execution. Programmers can use automated tools to convert design requirements into code.
Sometimes, vendors are subcontracted to develop all or part of the software--and even the hardware that it will run on--according to specified requirements. In these situations, vendors will bid on the subcontract by providing a proposal.
Testing is the process of finding errors and is one of the last activities in the software life cycle. In testing, we look to validate that software requirements analysis, software design, and software implementation mesh together correctly to deliver a software system that performs as expected, functionally and non-functionally.
As you review this unit, note the three levels of test plan: unit, integration, and system. Each of these levels of test plan assures the quality of the overall software from varying levels of granularity. In your own practice as a software engineer, be sure to incorporate these levels of testing as this is the last stop before the software goes out the door representing your professional work and code of ethics.
Project management in a software engineering environment is unique because of the technical aspects of a software project. The project manager's role is different from that of the software engineer's. While software engineers are generally accountable for the technical aspects of a project, the project manager is accountable for organizational aspects.
As you review the materials of the unit, try to connect this unit with what you have already learned about the software development life cycle. You will see that the success of an SDLC depends on people, process and product. Project management is the glue that holds these aspects together.
This unit pulls together the object-oriented methodology in software requirements analysis (i.e. Unit 5) and software design (i.e. Unit 6). You will apply UML to demonstrate your understanding of the software development life cycle given a set of user requirements. You will also have the opportunity to apply software testing to assess the quality of your work.
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