Software Engineering and Computer Science part 2
A student asked me: “Why do I need to study Software Engineering instead of Computer Science? Afterall, they are the same and after graduate, we will work in the software industry anyway?”
Answer: “Software Engineer and Computer Science are NOT the same. Each field focuses on different aspects of computing technology and lead to different careers in the software industry. In the past, most software are small and simple, so the focusing is on the “Science of algorithm development” or efficient code to run on computers. For example, storing information or automate a mathematic formula or process. That is why most Computer Science programs require many years of mathematics and several programming languages. Today, software are larger and more complex, so the focusing is on the “Engineering of process management” or efficient software development to solve complex issues. For example, one of the principle of software complexity is: “For every ten percent increase in problem complexity, there is an increase of one hundred percent in software solution complexity. The more complex the problem, the solution will be much more complex than previously thought. That is why you need to “Engineer the process” to solve the problem rather than relying on the “science of algorithm” to create efficient code.
Because the focus is on the entire development process, a Software Engineer will follow a set of rules and principles rather than jumps into a solution (write code) quickly. For example one of the most common causes of projects failure is unstable requirements. A Software Engineer who studies “Requirement Engineering” will know how to review, validate, then prioritize these requirements to ensure that they are well defined and stable enough before moving on to the next phase of design. When move from requirements to design, a good Software Engineer who studies “Architect and Design” will know that beside the defined requirements, there are many “derived requirements.” As a matter of fact, there will be more “derived requirements” than the original requirements and that is why the design phase is often take longer to ensure everything is taken into consideration before moving into the implementation phase.
A Software Engineer rarely works in isolation but mostly in team as software development is always a team efforts. The knowledge and skills of each team member are critical to the project success. (Teamwork is always taught in Software Engineering program but not in Computer Science). Because the most important factor in solving complex problem is NOT the tools, NOT the algorithms, NOT the techniques but rather the skills of the developers themselves. A highly skilled developers can be more productive (up to 30 times better) than a mediocre developers.
Computer science program focuses a lot on efficient code (Algorithm) so quality is mostly about software defects. However, Software Engineering program defines quality differently. Quality is a matter of good design than of good coding. If a project requires high quality then it must be considered early in the development life cycle. Quality is a collection of attributes such as performance, usability, portability, reliability, efficiency, testability, understandability, and modifiability. Software Engineering also believe that quality is not the same as satisfying users, meeting requirements, or meeting cost and schedule targets but they are all related. Actually, user satisfaction = quality product + meets requirements + delivered when needed + appropriate cost.
Computer science program focuses on detection and removal of defects. (Most developers spends roughly 40 percent of their time in testing). Programming and Testing are the important factors in the Computer Science program. Software Engineering program focuses more on the quality of the development process because they believe that the quality of the software product depends on the quality of the process that creates the product. By focusing more at each phase, remove defects at each phase then in the end you will have less defects to deal with. Instead of more time on testing, software engineers are focusing more on inspections, reviews at each phase. (In reality, there is no single best approach to software defect removal. A combination of several approaches, such as inspections, reviews, and testing, is necessary).
Although both programs graduates will start in the software industry in similar positions such as programmers, testers, and technical leaders. Over time, most Computer Science graduates will be working more on the technical side focusing on sophisticated algorithms, scientific methods, formal methods etc. Most Software Engineering graduates will be working on the management side focusing on project management, system architect, portfolio management, and process improvement.
Sources
- Blogs of Prof. John Vu, Carnegie Mellon University
