Cleanroom software development

The 'cleanroom' software development process is a technical and organizational approach to developing software with certifiable reliability. Key ideas behind the process are well structured software specifications, randomized testing methods and the introduction of statistical controls; but the main point is to deny entry for defects during the development of software. This latter point suggests the use of the term 'cleanroom' in analogy to the defect prevention controls used in the manufacturing of high technology hardware. In the 'cleanroom', the entire software development process is embedded within a formal statistical design, in contrast to executing selected tests and appealing to the randomness of operational settings for drawing statistical inferences. Instead, random testing is introduced as a part of the statistical design itself so that when development and testing are completed, statistical inferences are made about the operation of the system

Exploring Documentation: A Trivial Dimension of RUP

The Unified Process (UP) methodology is a commonly used methodology which can be followed by that entire process model where perfectly documented and well defined structure of team is needed, like Rational Unified Process (RUP) model which follows the UP methodology.  During documentation, the defect rate of software can be reduced and software quality can be improved. Quality is the sole objective which is pursued by stakeholders throughout the whole life cycle of software development. Quality is not the outcome of an accident; it is the fruit of the continual labor of devoted professionals. As the size of software increases, it is natural for the number of errors and defects to increase. The Cleanroom Software engineering process is a process for software development. The basic objective of Cleanroom Software engineering is to produce high quality of software emphasizing to increase the level of reliability to its utmost efficiency. Moreover, the Cleanroom process is involved in each and every phase of software development life cycle i.e. planning; measurement; specifying design; verifying code; testing; and certifying to mold the entire engineering discipline that the end product should result ideally in zero defect-rate. Keywords: Cleanroom software Engineering process, Documentation, Defect rate, Rational Unified process, quality and reliability

Experimental Evaluation of the Cleanroom Software Development Method

The field of software engineering is evolving as various new techniques, languages, paradigms, process models, methodologies, metrics etc., are constantly being developed, used and improved. In the past, several empirical studies were conducted to experiment with various new ideas in software engineering in order to help us better understand, evaluate, predict, control and improve these ideas. Basiii et al. review several of these studies and present a general framework for analyzing these experiments[2.5]. They emphasize the need of such experiments for advancement of software engineering discipline. They recommend that the experimental planning process should include a series of experiments for exploration, verification, and application of new ideas. They also implied that the results of empirical experiments in software engineering should be verified by a series of other related experiments. Cleanroom methodology for software development is a relatively new concept. Currently researchers are attempting to study the benefits and implications of using the Cleanroom methodology. One such attempt was made at the University of Maryland (UM) a few years ago which empirically characterized various aspects of Cleanroom methodologyj211. The fact that this study was empirical motivates the need for verifying its results. Also, the fact that the methodology is new motivates the need for further experimentation. Therefore, this experiment has been replicated recently at Miami University (MU). The goal of this project is to analyze the data collected in this experiment to verify the results of the previous study

The cleanroom case study in the Software Engineering Laboratory: Project description and early analysis

This case study analyzes the application of the cleanroom software development methodology to the development of production software at the NASA/Goddard Space Flight Center. The cleanroom methodology emphasizes human discipline in program verification to produce reliable software products that are right the first time. Preliminary analysis of the cleanroom case study shows that the method can be applied successfully in the FDD environment and may increase staff productivity and product quality. Compared to typical Software Engineering Laboratory (SEL) activities, there is evidence of lower failure rates, a more complete and consistent set of inline code documentation, a different distribution of phase effort activity, and a different growth profile in terms of lines of code developed. The major goals of the study were to: (1) assess the process used in the SEL cleanroom model with respect to team structure, team activities, and effort distribution; (2) analyze the products of the SEL cleanroom model and determine the impact on measures of interest, including reliability, productivity, overall life-cycle cost, and software quality; and (3) analyze the residual products in the application of the SEL cleanroom model, such as fault distribution, error characteristics, system growth, and computer usage

An Analysis of Early Software Reliability Improvement Techniques

This research explores early life cycle software reliability prediction models or techniques to predict the reliability of software prior to writing code, and a method for increasing or improving the reliability of software products early in the development life cycle. Five prediction models and two development techniques are examined. Each model is statically analyzed in terms of availability of data early in the life cycle, ease of data collection, and whether data is currently collected. One model and the two techniques satisfied those requirements and are further analyzed for their ability to predict or improve software reliability. While the researchers offer no significant statistical results of the model\u27s ability to predict software reliability, important conclusions are drawn about the cost and time savings of using inspections as a means of improving software reliability. The results indicate that the current software development paradigm needs to be changed to use the Cleanroom Software Development Process for fixture software development. This proactive approach to developing reliable software saves development and testing costs. One obvious benefit of this research is that cost savings realized earlier in the software development cycle have a dramatic effect on making software development practices better and more efficient

Conceptual design and multidisciplinary optimisation of power device for solar powered aircraft

Solar-powered aircraft is propelled by a photovoltaic cell that converts solar energy into electrical energy. The extra energy is stored in a rechargeable battery for later use when solar energy is not available. The performance of solar-powered aircraft is limited to solar radiation availability, low efficiency of the photovoltaic cell, and low energy density of the rechargeable battery. The research aims to improve the power device sizing, reduce the aircraft's mass, and improve the flight duration for sustainable flight operations for solar-powered aircraft (CLOUD 1). This was achieved using a multidisciplinary optimisation tool, a commercial package ModeFrontier software. Photovoltaic Geographic information system (PVGIS) software was used to obtain a solar radiation model for Malaysia. The model was used to develop both the energy balance and mission path for Malaysia to facilitate the availability and utilisation of solar energy for successful flight operations. Airfoil analysis was conducted. WE.3.55.9.3 airfoil was the best-chosen airfoil used for the wing design, while the empennage design, NACA 0008, was the most suitable. Hence, the latter was used for horizontal and vertical tail design with XFLR5 v6 software's aid. A novel methodology for the power device sizing was developed on MS Excel with 435.48Wh, 540.96Wh, 32, and 70 as the total required electrical energy, available solar energy, number of solar cells required, and the number of batteries required, respectively. The optimisation strategy embraced ModeFrontier software with the goal set to; minimise total electrical energy required, minimise the total mass, and maximise the available solar energy. The optimisation results show that available solar energy was 283.56Wh, the total electrical power required was 228.32Wh, the number of solar cells was 16, and the number of batteries was 36. The total mass of the aircraft was 2.05 Kg, respectively. The optimisation results achieved 53%, 51%, and 26% reductions in the number of solar cells, the number of batteries, and the aircraft's mass. Also, the flight duration was improved by 33%. The optimal configuration was used to design the solar-powered aircraft (CLOUD I)

The Software Engineering Laboratory: An operational software experience factory

For 15 years, the Software Engineering Laboratory (SEL) has been carrying out studies and experiments for the purpose of understanding, assessing, and improving software and software processes within a production software development environment at NASA/GSFC. The SEL comprises three major organizations: (1) NASA/GSFC, Flight Dynamics Division; (2) University of Maryland, Department of Computer Science; and (3) Computer Sciences Corporation, Flight Dynamics Technology Group. These organizations have jointly carried out several hundred software studies, producing hundreds of reports, papers, and documents, all of which describe some aspect of the software engineering technology that was analyzed in the flight dynamics environment at NASA. The studies range from small, controlled experiments (such as analyzing the effectiveness of code reading versus that of functional testing) to large, multiple project studies (such as assessing the impacts of Ada on a production environment). The organization's driving goal is to improve the software process continually, so that sustained improvement may be observed in the resulting products. This paper discusses the SEL as a functioning example of an operational software experience factory and summarizes the characteristics of and major lessons learned from 15 years of SEL operations

Cost-benefit analysis for software process improvement

Justification of investments to improve software development processes and technol- ogy continues to be a significant challenge for software management. Managers interested in improving quality, cost, and cycle-time of their products have a large set of methods, tools, and techniques from which to choose. The implementation of one or more of these potential improvements can require considerable time and cost. Decision makers must be able to understand the benefits from each proposed improvement and decide which improvements to implement. While a variety of approaches exist for evaluating the costs and benefits of a few specific improvements such as inspections or systematic reuse, there is no general model for evaluating software process improvements. The result of this research is a practical, useful framework to assist practitioners in evaluating potential process improvements. This general framework can accommodate a variety of methods for estimating the cost-benefit effects of a process change. To illustrate this framework a set of cost-benefit templates for Emerald and Cleanroom technologies were developed and validated. Methods for evaluating effects range from constants and simple equations to bayesian decision models and dynamic process simulations. A prototype tool was developed to assist in performing cost-benefit analysis of software process improvements

Effects of processing on the stability of molybdenum oxide ultra-thin films

The effects of wet chemical processing conventionally employed in device fabrication standards are systematically studied on molybdenum oxide (MoOx) ultra-thin films. We have combined x-ray photoelectron spectroscopy (XPS), angle resolved XPS and x-ray reflectivity techniques to provide deep insights into the changes in composition, structure and electronic states upon treatment of films with different initial stoichiometry prepared by reactive sputtering. Our results show significant reduction effects associated with the development of gap states in MoOx, as well as changes in the composition, density and structure of the films, systematically correlated with the initial oxidation state of Mo.Comment: 16 pages, 5 figures, Appendix include