Software Engineering Lecture 01 PDF

Software Engineering Dr. Fatma ElSayed Computer Science Department [email protected] 2024/2025 Software Engineering – Fatma ElSayed  Course Information Contents  Introduction to Software Engineer...

Software Engineering Dr. Fatma ElSayed Computer Science Department [email protected] 2024/2025 Software Engineering – Fatma ElSayed  Course Information Contents  Introduction to Software Engineering  Software Processes  Requirements Engineering  System Design  System Modelling  System Architecture  Software Testing Strategies  Software Testing Techniques  Technical Metrics for Software 2 2024/2025 Software Engineering – Fatma ElSayed  Course Information Contents  Introduction to Software Engineering  Software Processes  Requirements Engineering  System Design  System Modelling  System Architecture  Software Testing Strategies  Software Testing Techniques  Technical Metrics for Software 3 2024/2025 Software Engineering – Fatma ElSayed  Chapter 1: Introduction to Software Engineering 2024/2025 Software Engineering – Fatma ElSayed  What is Software?  Computer programs and associated documentation.  Software is not just the programs themselves but also all associated documentation that is required to set up these programs and make them operate correctly, explains how to use the system, and websites for users to download recent product information.  Software engineering is intended to support professional software development, rather than individual programming. Professional software, intended for use by someone apart from its developer, is usually developed by teams rather than individuals. It is maintained and changed throughout its life. 5 2024/2025 Software Engineering – Fatma ElSayed  Attributes of Good Software  The software should deliver the required functionality and performance to the user. Four important attributes that professional software must have: Maintainability Dependability Efficiency Acceptability Software must meet Software must be Software should not make Software must accepted by the changing needs and future trustworthy, shouldn't cause wasteful use of system users for which it was designed. upgrades can be made easily, physical or economic resources, memory and This means it must be quickly, and cheaply damage in case of system processor usage should be understandable, usable and compatible with other systems. failure minimized 6 2024/2025 Software Engineering – Fatma ElSayed  What is Software Engineering?  Software engineering is an engineering discipline that is concerned with all aspects of software production using systematic well-defined scientific techniques.  The result of software engineering is an effective and reliable software product.  Software engineers should adopt a systematic approach, using appropriate tools and techniques based on the problem, constraints, and resources.  Software engineers design, develop, and test software programs that apply computer technology to everyday processes. 7 2024/2025 Software Engineering – Fatma ElSayed  Software Engineer vs Software Developer Software Developer Software Engineer  A professional who builds software which  A professional who applies the principles runs across various types of computer. of software engineering for designing, development, maintenance, and testing computer software  Primarily a solitary activity.  Team activity.  Write a complete program.  Works with other components of the hardware system whereas software.  Use readymade tools to build apps.  Creates the tools to develop software.  Tend to do everything engineer do, but on a  Tend to solve issues on a much larger scale limited scale. 8 2024/2025 Software Engineering – Fatma ElSayed  Software Engineering vs. System Engineering & Computer Science  System engineering is concerned with all aspects of computer-based systems development including hardware, software, human work, and procedures needed to fulfill this mission. Software engineering is part of this process concerned with developing the software.  Computer science focuses on theory and fundamentals (programming languages, graphics, artificial intelligence and machine learning,….); software engineering is concerned with the practicalities of developing and delivering useful software.  Computer science gives the scientific foundation for software as electrical engineering depends on physics 9 2024/2025 Software Engineering – Fatma ElSayed  Software Products  Software products are software systems delivered to a customer with the documentation which describes how to install and use the system. Software Products Generic Products Customized Products These are stand-alone systems that are These are systems that are specially built produced by a development organization and for a particular customer. The software is sold on the open market to any customer developed especially for that customer who is able to buy them. by some developer. 10 2024/2025 Software Engineering – Fatma ElSayed  Software Products Generic Products Customized Products Universal software produced for the Unique solution for specific open market customers Examples: Examples: Software for PCs such as databases, Systems written to support a word processors, drawing packages, particular business process, and project-management tools. admission and registration system for some universities, air traffic control systems, and control systems for electronic devices 11 2024/2025 Software Engineering – Fatma ElSayed  Difference between Generic and Customized Comparison Generic Custom parameter Functionality has functionality designed to resolve a has functionality made to resolve a specific problem for several entities. problem for a specific entity. Specifications are produced internally by the according to a contract between marketing department of the product customer and developer company Quality quality isn’t the most parameter a quality is the main criterion in custom development company follows software product Number of users large limited users Marketing marketing is required marketing is not required Needs and updates defined by market demand custom software is done according to generic software is done based on the time, budget and needs are defined future updates by the customer Development cost usually not high high(single customer) 12 2024/2025 Software Engineering – Fatma ElSayed  Software Process  A software process is a sequence of activities that leads to the production of a software product.  Different types of systems need different development processes.  There are four fundamental activities that are common to all software processes. Specification Development [Design, Implementation] Validation Evolution 13 2024/2025 Software Engineering – Fatma ElSayed  Software Process: Activities Specification Development Validation Evolution where customers and where the where the where the engineers define the software is software is software is software that is to be designed and evaluated to updated to produced and the programmed. confirm that it reflect changing constraints on its meets the demands. operation. customer's what the system should production of the requirements. do and its development software constraints 14 2024/2025 Software Engineering – Fatma ElSayed  Key Challenges facing Software Engineering  Any company is going to develop new software it should deal with these key challenges 1. Coping with increasing diversity (Heterogeneity) The diversity of software and hardware platforms and fast changing in technology should not affect the developing software. 2. Demands for reduced delivery times (Delivery) Developing techniques that lead to faster delivery of software. 3. Developing trustworthy software. (Trust) Developing techniques that demonstrate that software can be trusted by its users. 15 2024/2025 Software Engineering – Fatma ElSayed  Software Costs  Roughly 60% of costs are development costs, 40% are testing costs. For custom software, evolution costs often exceed development costs.  Costs vary depending on the type of system being developed and the requirements of system attributes such as performance and system reliability.  Distribution of costs depends on the development model that is used.  Software engineering is concerned with cost-effective software development. 16 2024/2025 Software Engineering – Fatma ElSayed  Best Software Engineering Techniques and Methods  While all software projects have to be professionally managed and developed, different types of software systems require different development techniques.  You can’t, therefore, say that one method is better than another.  There are no universal software engineering methods and techniques that are suitable for all systems and all companies.  The key factor in choosing software engineering methods and techniques is the type of application being developed. 17 2024/2025 Software Engineering – Fatma ElSayed  Different Types of Application 1. Stand-alone applications They are designed to operate independently on a local computer without requiring a network connection. They include all the necessary components and functionalities within the application itself. Examples: office applications on a PC, photo manipulation software, etc. 2. Embedded control systems They are specialized software systems designed to control and manage hardware devices. They are tailored for performance and integration with the hardware components. Examples: software that controls anti-lock braking in a car, and software in a microwave oven to control the cooking process. 18 2024/2025 Software Engineering – Fatma ElSayed  Different Types of Application 3. Interactive transaction-based applications They are designed to allow users to interact with a remote system through their own PCs or terminals. These applications enable real-time user interaction with a remote system. Users can perform actions, make queries, and receive responses from the system. Examples: e-commerce applications (e.g. Amazon), online banking systems. 4. Batch processing systems These are business systems that are designed to process data in large batches rather than in real time. This approach is often used for tasks that don't require immediate processing. They process large numbers of individual inputs to create corresponding outputs. Examples: include periodic billing systems (phone billing systems). 19 2024/2025 Software Engineering – Fatma ElSayed  Different Types of Application 5. Data collection systems These systems are designed to gather data from various sources through sensors and transmit this data to other systems for further processing or analysis. They often operate in challenging environments, such as within engines or remote locations, and the software must be robust enough to handle these conditions while interacting with the sensors effectively. Examples: agricultural systems (use sensors to collect data on soil moisture, crop health, and weather conditions) and healthcare monitoring systems ( wearable devices and medical sensors collect data on vital signs such as heart rate, blood glucose levels, and oxygen saturation) 20 2024/2025 Software Engineering – Fatma ElSayed  Different Types of Application 6. Entertainment systems These are systems that are primarily for personal use and which are intended to entertain the user. 7. Systems for modelling and simulation These are systems that are developed by scientists and engineers to model physical processes or situations, which include many, separate, interacting objects. 8. Systems of systems These are systems that are composed of a number of other software systems. 21 2024/2025 Software Engineering – Fatma ElSayed  Software Engineering Fundamentals  Some fundamental principles apply to all types of software system, irrespective of the development techniques used: Systems should be developed using a managed and understood development process. Of course, different processes are used for different types of software. Dependability and performance are important for all types of system. Understanding and managing the software specification and requirements (what the software should do) are important. Where appropriate, you should reuse software that has already been developed rather than write new software. 22 2024/2025 Software Engineering – Fatma ElSayed  Software Engineering and the web  The Web is now a platform for running application and organizations are increasingly developing web-based systems rather than local systems.  Web services allow application functionality to be accessed over the web.  Cloud computing is an approach to the provision of computer services where applications run remotely on the ‘cloud’. Users do not buy software buy pay according to use. 23 2024/2025 Software Engineering – Fatma ElSayed  Software Engineering Ethics 24 2024/2025 Software Engineering – Fatma ElSayed  Professional and Ethical Responsibility  Software engineering involves wider responsibilities than simply the application of technical skills.  Software engineers must behave in an honest and ethically responsible way if they are to be respected as professionals.  Ethical behavior is more than simply upholding the law. 25 2024/2025 Software Engineering – Fatma ElSayed  Issues of Professional Responsibility  Confidentiality Engineers should normally respect the confidentiality of their employers or clients of whether or not a formal confidentiality agreement has been signed. (Keep sensitive information private and protected from unauthorized individuals or entities.)  Competence Engineers should not misrepresent your level of competence. They should be honest about their abilities, skills, and qualifications. (If a task or job is outside their current level of expertise, they should avoid accepting it, as doing so could lead to poor performance, errors, or harm to the employer, client, or project) 26 2024/2025 Software Engineering – Fatma ElSayed  Issues of Professional Responsibility  Intellectual property rights Engineers should be aware of local laws governing the use of intellectual property such as patents, copyright, etc. They should be careful to ensure that the intellectual property of employers and clients is protected.  Computer misuse Software engineers should not use their technical skills to misuse other people’s computers. Computer misuse ranges from relatively trivial (game playing on an employer’s machine) to extremely serious (spreading of viruses). e.g. Test software for the company or client. This could involve accessing the computer to install programs, run tests, or troubleshoot issues. 27 2024/2025 Software Engineering – Fatma ElSayed  ACM/IEEE Code of Ethics  The professional societies in the US have cooperated to produce a code of ethical practice.  The Code contains eight Principles related to the behavior of and decisions made by professional software engineers, including practitioners, educators, managers, supervisors, and policy makers, as well as trainees and students of the profession. (Software engineers should follow in their professional work. By following this code, software engineers ensure they behave ethically, contribute positively to society, and maintain trust in their profession.) 28 2024/2025 Software Engineering – Fatma ElSayed  29 2024/2025 Software Engineering – Fatma ElSayed  Ethical Dilemmas  In any situation where different people have different views and objectives you are likely to be faced with ethical dilemmas. Disagreement in principle with the policies of senior management. (conflict between your own moral principles or professional values) Your employer acts in an unethical way and releases a safety-critical system without finishing the testing of the system. Participation in the development of military weapons systems or nuclear systems. 30 2024/2025 Software Engineering – Fatma ElSayed  Case studies 1. A personal insulin pump An embedded system in an insulin pump used by diabetics to maintain blood glucose control. 2. A mental health case patient management system Mentcare. A system used to maintain records of people receiving care for mental health problems. 3. A wilderness weather station A data collection system that collects data about weather conditions in remote areas. 31 2024/2025 Software Engineering – Fatma ElSayed  NEXT: Software Processes 2024/2025 Software Engineering – Fatma ElSayed  Thanks!.. Questions? 2024/2025 Software Engineering – Fatma ElSayed