Lect5 improving software economics
- 2. Five basic parameters of the software cost model are: 1.Reducing the size or complexity of what needs to be developed. 2. Improving the development process. 3. Using more-skilled personnel and better teams (not necessarily the same thing). 4. Using better environments (tools to automate the process). 5. Trading off or backing off on quality thresholds.
- 4. 1. REDUCING SOFTWARE PRODUCT SIZE To improve affordability and return on investment (ROI) and to produce a product that achieves the design goals with the minimum amount of human-generated source material. • Component-based development is helpful for reducing the "source" language size to achieve a software solution. • Reuse, object-oriented technology, automatic code production, and higher order programming languages are all focused on achieving a given system with fewer lines of human-specified source directives. • Size reduction is the primary motivation behind improvements in higher order languages (such as C++, Ada 95, Java, Visual Basic), automatic code generators (CASE tools, visual modeling tools, GUI builders), reuse of commercial components (operating systems, windowing environments, DBMS, middleware, networks), and OOPS technologies (Unified Modeling Language, visual modeling tools, architecture frameworks). • The reduction is defined in terms of human-generated source material. In general, when size-reducing technologies are used, they reduce the number of human-generated source lines.
- 5. 1.1 LANGUAGES • Universal function points (UFPs1) are useful estimators for language- independent, early life-cycle estimates. The basic units of function points are external user inputs, external outputs, internal logical data groups, external data interfaces, and external inquiries. • SLOC metrics are useful estimators for software after a candidate solution is formulated and an implementation language is known. • Substantial data have been documented relating SLOC to function points.
- 6. 1.2 OBJECT-ORIENTED METHODS AND VISUAL MODELING • Object-oriented programming languages benefit both software productivity and software quality. The fundamental impact of object- oriented technology is in reducing the overall size of what needs to be developed. • People like drawing pictures to explain something to others or to themselves. When they do it for software system design, they call these pictures diagrams or diagrammatic models and the very notation for them a modeling language. Some examples of the interrelationships among the dimensions of improving software economics. 1. An object-oriented model of the problem and its solution encourages a common vocabulary between the end users of a system and its developers, thus creating a shared understanding of the problem being solved. 2. The use of continuous integration creates opportunities to recognize risk early and make incremental corrections without destabilizing the entire development effort. 3. An object-oriented architecture provides a clear separation of concerns among disparate elements of a system, creating firewalls that prevent a change in one part of the system from rending the fabric of the entire architecture.
- 7. Five characteristics (as per Booch )of a successful object- oriented project. 1. A ruthless focus on the development of a system that provides a well understood collection of essential minimal characteristics. 2. The existence of a culture that is centered on results, encourages communication, and yet is not afraid to fail. 3. The effective use of object-oriented modeling. 4. The existence of a strong architectural vision. 5. The application of a well-managed iterative and incremental development life cycle.
- 8. 1.3 REUSE • Reusing existing components and building reusable components have been natural software engineering activities. • With reuse in order to minimize development costs while achieving all the other required attributes of performance, feature set, and quality. • Try to treat reuse as a mundane part of achieving a return on investment. • Most truly reusable components of value are transitioned to commercial products supported by organizations with the following characteristics: • They have an economic motivation for continued support. • They take ownership of improving product quality, adding new features, and transitioning to new technologies. • They have a sufficiently broad customer base to be profitable. • The cost of developing a reusable component is not trivial • Reuse is an important discipline that has an impact on the efficiency of all workflows and the quality of most artifacts
- 9. 1.4 COMMERCIAL COMPONENTS • Try to maximize integration of commercial components and off-the-shelf products. • The use of commercial components is certainly desirable as a means of reducing custom development
- 10. 2. IMPROVING SOFTWARE PROCESSES 3 level of Process can be identified in an organisation: • Metaprocess: an organization's policies, procedures, and practices for pursuing a software-intensive line of business. The focus of this process is on organizational economics, long-term strategies, and software ROI. • Macroprocess: a project's policies, procedures, and practices for producing a complete software product within certain cost, schedule, and quality constraints. The focus of the macro process is on creating an adequate instance of the Meta process for a specific set of constraints. • Microprocess: a project team's policies, procedures, and practices for achieving an artifact of the software process. The focus of the micro process is on achieving an intermediate product baseline with adequate quality and adequate functionality as economically and rapidly as practical.
- 12. 3. IMPROVING TEAM EFFECTIVENESS Teamwork is much more important than the sum of the individuals. With software teams, a project manager needs to configure a balance of solid talent with highly skilled people in the leverage positions. Some maxims of team management include the following: • A well-managed project can succeed with a nominal engineering team. • A mismanaged project will almost never succeed, even with an expert team of engineers. • A well-architected system can be built by a nominal team of software builders. • A poorly architected system will flounder even with an expert team of builders. • Boehm five staffing principles are • 1. The principle of top talent: Use better and fewer people • 2. The principle of job matching: Fit the tasks to the skills and motivation of the people available. • 3. The principle of career progression: An organization does best in the long run by helping its people to self-actualize. • 4. The principle of team balance: Select people who will complement and harmonize • 5. The principle of phase-out: Keeping a misfit on the team doesn't benefit anyone
- 13. Software project managers need many leadership qualities in order to enhance team effectiveness. Attributes of successful software project managers : • Hiring skills. Few decisions are as important as hiring decisions. Placing the right person in the right job seems obvious but is surprisingly hard to achieve. • Customer-interface skill. Avoiding adversarial relationships among stakeholders is a prerequisite for success. • Decision-making skill. The jillion books written about management have failed to provide a clear definition of this attribute. We all know a good leader when we run into one, and decision-making skill seems obvious despite its intangible definition. • Team-building skill. Teamwork requires that a manager establish trust, motivate progress, exploit eccentric prima donnas, transition average people into top performers, eliminate misfits, and consolidate diverse opinions into a team direction. • Selling skill. Successful project managers must sell all stakeholders (including themselves) on decisions and priorities, sell candidates on job positions, sell changes to the status quo in the face of resistance, and sell achievements against objectives. In practice, selling requires continuous negotiation, compromise, and empathy
- 14. IMPROVINGAUTOMATION THROUGH SOFTWARE ENVIRONMENTS • The tools and environment have a linear effect on the productivity of the process. • Planning tools, requirements management tools, visual modeling tools, compilers, editors, debuggers, quality assurance analysis tools, test tools, and user interfaces provide crucial automation support for evolving the software engineering artifacts. • configuration management environments provide the foundation for executing and instrument the process. • At first order, the isolated impact of tools and automation generally allows improvements of 20% to 40% in effort. • tools and environments must be viewed as the primary delivery vehicle for process automation and improvement, so their impact can be much higher. • Automation of the design process provides payback in quality, the ability to estimate costs and schedules, and overall productivity using a smaller team. • .
- 15. • Round-trip engineering describes the key capability of environments that support iterative development. As we have moved into maintaining different information repositories for the engineering artifacts, we need automation support to ensure efficient and error-free transition of data from one artifact to another. • Forward engineering is the automation of one engineering artifact from another, more abstract representation. (compilers and linkers have provided automated transition of source code into executable code). • Reverse engineering is the generation or modification of a more abstract representation from an existing artifact (for example, creating a visual design model from a source code representation).
- 16. • Requirements analysis and evolution activities consume 40% of life-cycle costs. • Software design activities have an impact on more than 50% of the resources. • Coding and unit testing activities consume about 50% of software development effort and schedule. • Test activities can consume as much as 50% of a project's resources. • Configuration control and change management are critical activities that can consume as much as 25% of resources on a large-scale project. • Documentation activities can consume more than 30% of project engineering resources. • Project management, business administration, and progress assessment can consume as much as 30% of project budgets.
- 17. ACHIEVING REQUIRED QUALITY • Software best practices are derived from the development process and technologies. Key practices that improve overall software quality include the following: • Focusing on driving requirements and critical use cases early in the life cycle, focusing on requirements completeness and traceability late in the life cycle, and focusing throughout the life cycle on a balance between requirements evolution, design evolution, and plan evolution • Using metrics and indicators to measure the progress and quality of an architecture as it evolves from a high-level prototype into a fully compliant product • Providing integrated life-cycle environments that support early and continuous configuration control, change management, rigorous design methods, document automation, and regression test automation • Using visual modeling and higher level languages that support architectural control, abstraction, reliable programming, reuse, and self-documentation • Early and continuous insight into performance issues through demonstration-based evaluations
- 19. Events in Performance Assessment • Project inception. The proposed design was asserted to be low risk with adequate performance margin. • Initial design review. Optimistic assessments of adequate design margin were based mostly on paper analysis or rough simulation of the critical threads. • Mid-life-cycle design review. The assessments started whittling away at the margin, as early benchmarks and initial tests began exposing the optimism inherent in earlier estimates. • Integration and test. Serious performance problems were uncovered, necessitating fundamental changes in the architecture. The underlying infrastructure was usually the scapegoat, but the real culprit was immature use of the infrastructure, immature architectural solutions, or poorly understood early design trade-offs.
- 20. PEER INSPECTIONS A PRAGMATIC VIEW Peer reviews are valuable, but they are rarely significant contributors to quality compared with the following primary quality mechanisms and indicators, which should be emphasized in the management process: • Transitioning engineering information from one artifact set to another, thereby assessing the consistency, feasibility, understandability, and technology constraints inherent in the engineering artifacts • Major milestone demonstrations that force the artifacts to be assessed against tangible criteria in the context of relevant use cases • Environment tools (compilers, debuggers, analyzers, automated test suites) that ensure representation rigor, consistency, completeness, and change control • Life-cycle testing for detailed insight into critical trade-offs, acceptance criteria, and requirements compliance • Change management metrics for objective insight into multiple- perspective change trends and convergence or divergence from quality and progress goals
- 21. • Inspections are also a good vehicle for holding authors accountable for quality products. • All authors of software and documentation should have their products scrutinized as a natural by-product of the process. • Therefore, the coverage of inspections should be across all authors rather than across all components.
- 22. References • Software Project management, Walker Royce, Addison Wesley, 1998. • https://www.javatpoint.com/software-project-management