Lect4 software economics
- 1. Evolution of Software Economics Dr Meena Malik(meenamlk@gmail.com)
- 2. SOFTWARE ECONOMICS The software cost models have five basic parameters: 1. Size number of source instructions or the number of function points required to develop the required functionality 2. Process used to produce the end product 3. Personnel the capabilities and experience of software engineering personnel, with the computer science issues and the applications domain. 4. Environment is made up of the tools and techniques available to support efficient software development and to automate the process 5. Quality of the product, including its features, performance, reliability, and adaptability
- 3. • The relationships among software cost five basic parameters and the estimated cost can be written as follows: Effort = (Personnel) (Environment) (Quality) ( Size process) • One important aspect of software economics is that the relationship between effort and size exhibits a diseconomy of scale. • The diseconomy of scale of software development is a result of the process exponent being greater than 1.0. • The more software you build, the more expensive it is per unit item.
- 4. Generations of software development 1) Conventional (craftsmanship) : 1960s and 1970sOrganizations used custom tools, custom processes, and virtually all custom components built in primitive languages. Project performance was highly predictable in that cost, schedule, and quality objectives were almost always underachieved. 2) Transition (software engineering) : 1980s and 1990sOrganizations used more-repeatable processes and off-the- shelf tools, and mostly (>70%) custom components built in higher level languages. Some of the components (<30%) were available as commercial products, including the operating system, database management system, networking, and graphical user interface. 3) Modern practices (software production ): 2000 and later,. Use of managed and measured processes, integrated automation environments, and mostly (70%).
- 7. PRAGMATIC SOFTWARE COST ESTIMATION • One critical problem in software cost estimation is a lack of well- documented case studies of projects that used an iterative development approach. • Software industry has inconsistently defined metrics or atomic units of measure, the data from actual projects are highly suspect in terms of consistency and comparability. • It is hard enough to collect a homogeneous set of project data within one organization; it is extremely difficult to homogenize data across different organizations with different processes, languages, domains, and so on. • There have been many debates among developers and vendors of software cost estimation models and tools. Three topics of these debates are of particular interest here: 1. Which cost estimation model to use? 2. Whether to measure software size in source lines of code or function points. 3. What constitutes a good estimate?
- 8. • There are several popular cost estimation models (such as COCOMO, CHECKPOINT, ESTIMACS, Knowledge Plan, Price-S, ProQMS, SEER, SLIM, SOFTCOST, and SPQR/20). • COCOMO is most open and well-documented cost estimation models. The general accuracy of conventional cost models (such as COCOMO) has been described as "within 20% of actuals, 70% of the time." A good software cost estimate has the following attributes: 1. It is conceived and supported by the project manager, architecture team, development team, and test team accountable for performing the work. 2. It is accepted by all stakeholders as ambitious but realizable. 3. It is based on a well-defined software cost model with a credible basis. 4. It is based on a database of relevant project experience that includes similar processes, similar technologies, similar environments, similar quality requirements, and similar people. 5. It is defined in enough detail so that its key risk areas are understood and the probability of success is objectively assessed.
- 10. References • Software Project management, Walker Royce, Addison Wesley, 1998. • https://www.javatpoint.com/software-project-management