Understanding Software Complexity
Explore the importance of software in everyday life, its role in business decisions, products and services, technology innovations, industry and entertainment, and economic significance. Learn about software's characteristics compared to hardware, complexity factors, inherent complexity, and more in this insightful overview.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
Source- https://vdocument.in Software Software Engineering LECTURE # 1
What is Software? Software is a set of items or objects that includes: programs data documents 2
Why is it important?
Importance of Software Software in everyday life Business decisions Products and services Technology and innovations Industry and entertainment Economic significance 4
Importance of Software Software acts as basis for: Control of computer operating systems Communication of information internet Creation and control of other programs software tools and environments 5
Hardware Vs. Software Hardware Software Does not wear out Wears out No spare parts Replaceable spare parts Software characteristics: Intangible Exhibits aging Complex Deteriorates (Decline, Depreciate) Defect prone 6
Hardware Vs. Software Wearout Infant Mortality Failure Rate Time Hardware Failure Curve 7
Wear Vs. Deterioration increased failure rate due to sideeffects Failure rate Software deteriorates and becomes complex change actualcurve idealized / theoretical curve Time 8
The source of inherent complexity in software The difference between a software system and a car !!
Complexity in Software Complexity of software arises from Complexity of problem domain Difficulty in managing development process Software evolution Direct consequence of software change is software defects The complexity of software is an essential property, not an accidental one 10
Cost of Software Software costs often dominate system costs. The costs of software on a PC are often greater than the hardware cost Software costs more to maintain than it does to develop. For systems with a long life, maintenance costs may be several times development costs 11
The Cost of Change 60-100x 1.5-6x 1x Afterrelease Development Definition 12
The name of the game is continuous change and evolution in all dimensions! 13
Engineering The study concerned with putting scientific knowledge to practical use Webster s Dictionary 14
Engineering A way of approaching a problem An approach to productively use scientific knowledge Examples: Electrical Engineering Mechanical Engineering Civil Engineering Physics as basic science 15
Difference between Computer Science and Software Engineering Software Engineering uses knowledge from Computer Scienceto effectively build software 16
Software Crisis A Historical Perspective (1950 s) The advent of more powerful and cheaper hardware resulted in more complex applications. The tools and technologies for primitive computer systems were inadequate for newer systems Resulted in Prolonged schedule slippages Astronomical development and maintenance costs Unreliable software systems Disappointment !!! Software was in Crisis 17
The Birth of Software Engineering Born in 1960 in a conference on Software Crisis Software Crisis resulted in realization that: Coding alone was not enough!! New techniques and methods were required to control the complexity inherent in LARGE software systems 18
The Birth of Software Engineering Decision There should be some engineering principles applied for the development of successful software The Term Software Engineering was coined 19
Software Engineering-Definitions IEEE The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software; that is, the application of engineering to software 20
Software Engineering-Definitions Ian Sommerville- All aspects of software production: Software engineering is not just concerned with the technical processes of software development, but also with activities such as software project management and with the development of tools, methods and theories to support software production 21
Software Engineering Software Engineering The set of processes and tools to develop software Software Engineering is not just about producing software, but about producing software in a COST- EFFECTIVE manner. 22
Software Engineering: Points to Remember SE is has a wide scope and is concerned with anything that has something to do with software SE is concerned with cost effective software development SE is NOT just coding; there is a lot more to it SE is nothing but a disciplined and systematic approach to developing software 23
No Silver Bullet Fred Brooks, The Mythical Man-month There is no short cut to software development Software can be disastrous to managers in the form of: Schedule slippages High costs Delivery of unreliable systems Begin upright and upfront with a systematic approach to building software 24
Characteristics of a Well Engineered Software Efficient User-friendly Cost-effective Reliable Provides the required functionality Maintainable 25
A software engineer is challenged to produce high- quality software with a finite amount of resources, within predicted schedule and budget 26
The Balancing Act Software requirements may be conflicting Cost vs. Efficiency Cost vs. Reliability Efficiency vs. User-interface 27
Challenge is to balance these requirements 28
Effort Breakdown Breakdown of activities involved in software development (Caper Jones) Project Management Requirements Design Coding SQA SCM Integration Miscellaneous 8.08% ~3% 30.64% 13.02% 6.54% 14.43% 11.36% 13.50% SE is NOT just Coding !! 29
Software nothing but a disciplined and systematic approach software development! (In a cost effective manner) Engineering is to 30
