Software Quality Cost Measurement PDF

IT2002 Objective and Cost of Software Quality Measurement………………….. The classic quality cost model, developed in the early 1950s by Feigenbaum and others, provides a methodology for classifying the co...

IT2002 Objective and Cost of Software Quality Measurement………………….. The classic quality cost model, developed in the early 1950s by Feigenbaum and others, provides a methodology for classifying the costs Cost of Software Quality - is the financial assessment of software quality associated with product quality assurance from a financial point of view. The development and maintenance – is just another class of software quality model was developed to suit quality settings in manufacturing organizations metrics, where financial values are used as the measuring tool. Managerial and has since been widely implemented. The model classifies quality costs control over the cost of software quality (CoSQ) is achieved by a into two general classes: comparison of actual performance figures with: Costs of Control - relate to costs controlled by the software Prevention and appraisal activities budget developer and includes the following subclasses: Previous year’s failure cost o Prevention Costs Previous project’s total quality o Appraisal Costs Other department’s quality cost Costs of Failure of Control - relate to the costs of correcting failures that occurred due to unsuccessful prevention activities. The Cost of Software Quality Measurement Objectives model further subdivides these costs into two subclasses: o Internal Failure Costs Control organization-initiated costs to prevent and detect software o External Failure Costs errors. Evaluate financial damages of software failures as a basis for Prevention Costs…………………………………………………….………….. revising the SQA budget. Evaluate plans to increase/decrease SQA activities, or to invest in Prevention Costs - include investments in establishing, updating, and new/updated SQA infrastructure. improving a software quality infrastructure, as well as for performing the regular activities required for its operation. Typical preventive costs include: The Classic Model of Cost of Software Quality…………………………….. a. Investments in the development of new or improved SQA infrastructure components or regular updating of these components: o Procedures and work instructions o Support devices o Software configuration management system o Software quality metrics b. Regular implementation of SQA preventive activities: o Instruction of new employees on SQA topics and procedures related to their positions o Instruction of employees in new and updated SQA topics and procedures o Certification of employees for specific positions o Analysis of errors and additional data and the subsequent performing of corrective and preventive actions c. Control of the SQA system through the performance of: o Internal quality audits o External quality audits by customers and SQA system certification organizations o Management quality reviews 05 Handout 1 *Property of STI  [email protected] Page 1 of 3  IT2002 Appraisal Costs……………………………………..……………….………….. Extended Model for Cost of Software Quality……………..……………….. Appraisal costs - include the cost of activities performed for a specific project or software system to detect software errors that need to be corrected. Typical appraisal costs cover: a. Reviews: o Formal reviews o Peer reviews o Expert reviews b. Cost of software testing o Unit tests o Integration tests o Software system tests o Acceptance tests c. External participants: o Subcontractors o Software system suppliers o Project participant Internal Failure Costs……………………………………………….………….. Internal failure costs - are those incurred through correcting errors that It extends the classic model to include management’s “contribution” to the were detected through design reviews, software tests, and acceptance tests total cost of software quality. The management quality costs are classified performed before the software was installed at customer sites. In other into two general classes: words, internal failure costs represent the cost of error correction subsequent to formal examinations of the software during its development. 1. Management Control Costs - relate to costs that are controlled Typical costs of internal failures: by the management and include two subclasses as follows: a. Cost of rework o Management Prevention Costs: Management b. Cost of design corrections subsequent to design reviews and test preventions costs are associated with activities performed findings to prevent managerial failures or reduce prospects of their c. Cost of correcting programs following test findings occurrence. These activities are required to be performed d. Regression tests before work commences on the project and are the e. Domino effect damages responsibility of management. It includes pre-project activities designed to detect erroneous proposal parts and External Failure Costs…………………………………………….………….. prepare appropriate plans for project performance. o Management Appraisal Costs: Management preparations and control costs are associated with activities External failure costs include all costs of correcting failures detected by performed to prevent managerial failures or reduce customers or maintenance teams after the software system has been prospects of their occurrence. Typical management installed at customer sites. These costs may be further classified into overt appraisal costs include the costs of activities to control the external failure costs and hidden external failure costs. performance of a specific project. 05 Handout 1 *Property of STI  [email protected] Page 2 of 3  IT2002 2. Management Failure of Control Costs - relates to the costs of Inaccurate and/or incomplete identification and classification of correcting failures that occurred due to unsuccessful prevention quality costs activities. Divides these costs into two subclasses: Negligent reporting by team members and others o Management Internal Failure Costs: Management Biased reporting of software costs, especially of “censored” internal internal failure costs may be incurred throughout the entire and external costs course of software development. They are most likely to Biased recording of external failure costs, due to indirect materialize in connection with failed attempts to identify compensation of customers for failures (e.g., discounted future project risks, failed estimates regarding the appropriate services, delivery of free services), whose implications are not project schedule and budget, as well as to detect in a timely recorded as external failure costs fashion those deviations and problems that necessitate management intervention. Problems Arising when Collecting Data on Managerial Prevention and o Management External Failure Costs: Naturally, most Appraisal Costs managerial external failure costs incurred after completion of software development and system installation. It includes Contract review and progress control activities are performed in additional error repairs at customer sites and damages paid many cases in a “part-time mode” and in addition, they are to customers due to customer-detected product faults subdivided into several disconnected activities of short duration. resulting from management commitments and failures. The reporting of time invested in these activities is usually inaccurate and often neglected. Application of Cost of Software Quality (CoSQ) System…………………. Many of the participants in these activities are senior staff members and are not required to report their time. In the first stage of applying a CoSQ model, the organization should choose The nature of follow-up activities requiring few hours, and in many its preferred type of cost model–classic or extended. Whichever model is cases, even less than an hour, makes them difficult to report selected, its effectiveness is determined to a great degree by the suitability accurately. for the organization of the cost items designed to be measured for the model. In other words, these model items, defined specifically for the Problems Encountered in Collection of Data on Managerial Failure organization, are considered relevant to the organization’s activities and Costs budget expenditures. In order to apply a cost of software quality system in Determination of responsibility for schedule failures: Schedule an organization, the following are required: failure costs are frequently deliberated for lengthy periods because Definition of a cost of software quality model and an array of cost their direct causes or the specific contributions of each participant items specifically for the organization, department, team, or project to the initial failures are difficult to pinpoint. Definition of a method of data collection Late payment of customer’s overt compensation: At the time of Application of a cost of software quality system, including thorough these compensations, it is too late for the effective application of the follow-up lessons learned. Actions to be taken in response to the findings produced ___________________________________________________________ Problems in Application of CoSQ Measurements…………………………. References: Application of a CoSQ model is generally accompanied by problems to be Galin, D. (2018). Software quality assurance: Concepts and practice. IEEE Computer Society, overcome, whatever the industry is. These impinge upon the accuracy and Inc. Laporte, C. and April, A. (2018). Software quality assurance. IEEE Computer Society, Inc. completeness of quality cost data caused by: 05 Handout 1 *Property of STI  [email protected] Page 3 of 3