In practice, the relative importance of particular software characteristics typically depends on software domain, product type, and intended usage. Thus, software characteristics should be defined for, and used to guide the development of, each product.
Quality function deployment provides a process for developing products based on characteristics derived from user needs. You can also search articles , case studies , and publications for software quality resources. Assessing Developer Quality Using Coding Challenges Software Quality Professional Coding challenges are often used as a step in evaluating software engineering and test automation candidates for development and quality assurance jobs.
But does the practice result in hiring better coders? This article uses a literature review to explore the best practices for coding challenges.
A Discussion of the Software Quality Assurance Role Software Quality Professional The inability to identify who are actually customers limits the ability of software quality assurance SQA engineers in the performance of their duties.
Correcting this oversight enables the SQA engineer to provide greater value to customers by assuming the role of auditor as well as that of software and systems engineer.
Becoming a Successful Software Manager Software Quality Professional If managers want their software projects to succeed, they must exemplify and drive a culture of quality in everything they do. For normally distributed values, use Pearson Correlation Coefficient to check whether or not the two variables are highly correlated.
For non- normal data, rank the data and use the Spearman Rank Correlation Coefficient as a measure of association. Another measure for non-normal data is the Kendall robust correlation coefficient , which investigates the relationship among pairs of data points and can identify a partial correlation. If the ranking contains a large number of tied values, a chi-squared test on a contingency table can be used to test the association between the variables.
Similarly, linear regression can be used to generate an equation to describe the relationship between the variables. At the same time, the complexity of analysis can influence the design chosen. For complex factorial designs with more than two factors, more sophisticated test of association and significance is needed. Statistical techniques can be used to account for the effect of one set of variables on others, or to compensate for the timing or learning effects.
Internal product attributes describe the software products in a way that is dependent only on the product itself. The major reason for measuring internal product attributes is that, it will help monitor and control the products during development.
The main internal product attributes include size and structure. Size can be measured statically without having to execute them. The size of the product tells us about the effort needed to create it. Similarly, the structure of the product plays an important role in designing the maintenance of the product. There are three development products whose size measurement is useful for predicting the effort needed for prediction.
They are specification, design, and code. These documents usually combine text, graph, and special mathematical diagrams and symbols. Specification measurement can be used to predict the length of the design, which in turn is a predictor of code length. The diagrams in the documents have uniform syntax such as labelled digraphs, data-flow diagrams or Z schemas.
Since specification and design documents consist of texts and diagrams, its length can be measured in terms of a pair of numbers representing the text length and the diagram length.
For these measurements, the atomic objects are to be defined for different types of diagrams and symbols. The atomic objects for data flow diagrams are processes, external entities, data stores, and data flows.
The atomic entities for algebraic specifications are sorts, functions, operations, and axioms. The atomic entities for Z schemas are the various lines appearing in the specification.
Code can be produced in different ways such as procedural language, object orientation, and visual programming. The most commonly used traditional measure of source code program length is the Lines of code LOC. Apart from the line of code, other alternatives such as the size and complexity suggested by Maurice Halsted can also be used for measuring the length. He proposed three internal program attributes such as length, vocabulary, and volume that reflect different views of size.
He began by defining a program P as a collection of tokens, classified by operators or operands. The basic metrics for these tokens were,.
Where the unit of measurement E is elementary mental discriminations needed to understand P. Object-oriented development suggests new ways to measure length.
Pfleeger et al. The amount of functionality inherent in a product gives the measure of product size. There are so many different methods to measure the functionality of software products. Function point metrics provide a standardized method for measuring the various functions of a software application.
Function point analysis is a standard method for measuring software development from the user's point of view. FP Function Point is the most widespread functional type metrics suitable for quantifying a software application. It is based on five users identifiable logical "functions", which are divided into two data function types and three transactional function types.
For a given software application, each of these elements is quantified and weighted, counting its characteristic elements, such as file references or logical fields. A distinct final formula is used for each count type: Application, Development Project, or Enhancement Project. These are elementary processes in which derived data passes across the boundary from outside to inside.
In an example library database system, enter an existing patron's library card number. These are elementary processes in which derived data passes across the boundary from inside to outside. In an example library database system, display a list of books checked out to a patron.
These are elementary processes with both input and output components that result in data retrieval from one or more internal logical files and external interface files. In an example library database system, determine what books are currently checked out to a patron. These are user identifiable groups of logically related data that resides entirely within the applications boundary that are maintained through external inputs.
In an example library database system, the file of books in the library. These are user identifiable groups of logically related data that are used for reference purposes only, and which reside entirely outside the system.
In an example library database system, the file that contains transactions in the library's billing system. Based on the following table, an EI that references 2 files and 10 data elements would be ranked as average. Based on the following table, an ILF that contains 10 data elements and 5 fields would be ranked as high. Weigh each GSC on a scale of 0 to 5 based on whether it has no influence to strong influence.
It has two aspects. One aspect of complexity is efficiency. It measures any software product that can be modeled as an algorithm. For example: If an algorithm for solving all instances of a particular problem requires f n computations, then f n is asymptotically optimal, if for every other algorithm with complexity g that solves the problem f is O g. Measurement of structural properties of a software is important for estimating the development effort as well as for the maintenance of the product.
The structure of requirements, design, and code helps understand the difficulty that arises in converting one product to another, in testing a product, or in predicting the external software attributes from early internal product measures. The control flow measures are usually modeled with directed graph, where each node or point corresponds to program statements, and each arc or directed edge indicates the flow of control from one statement to another.
Theses graphs are called control-flow graph or directed graph. Data flow or information flow can be inter-modular flow of information within the modules or intra-modular flow of information between individual modules and the rest of the system. Locally , the amount of structure in each data item will be measured. A graph-theoretic approach can be used to analyze and measure the properties of individual data structures.
In that simple data types such as integers, characters, and Booleans are viewed as primes and the various operations that enable us to build more complex data structures are considered. Data structure measures can then be defined hierarchically in terms of values for the primes and values associated with the various operations. Several national and international standards institutes, professional and industry-oriented organizations have been involved in the development of SQA standards.
These organizations provide updated international standards to the quality of professional and managerial activities performed in software development and maintenance organizations. They also provide SQA certification through independent professional quality audits. These external audits assess achievements in the development of SQA systems and their implementation. Certification, which is granted after the periodic audits, will be valid only until the next audit, and therefore must be renewed.
Software quality assurance management standards, including certification and assessment methodologies quality management standards. With quality management standards, organizations can steadily assure that their software products achieve an acceptable level of quality. These focus on the methodologies for implementing the software development and maintenance projects.
Naturally, due to their characteristics, many SQA standards in this class can serve as software engineering standards and vice versa.
ISO the International Organization for Standardization is a worldwide federation of national standards bodies. ISO technical committees prepare the International Standards. Draft of the International Standards adopted by the technical committees is circulated to the member bodies for voting. This International Standard promotes the adoption of a process approach when developing, implementing, and improving the effectiveness of a quality management system, to enhance customer satisfaction by meeting the customer requirements.
For an organization to function effectively, it has to determine and manage numerous linked activities. An activity or set of activities using resources, and managed in order to enable the transformation of inputs into outputs, can be considered as a process.
Often the output from one process directly forms the input to the next. An advantage of the process approach is the ongoing control that it provides over the linkage between the individual processes within the system of processes, as well as over their combination and interaction.
TickIT was launched in the late s by the UK software industry in cooperation with the UK Department for Trade and Industry to promote the development of a methodology for adapting ISO to the characteristics of the software industry known as the TickIT initiative.
TickIT is, additionally, specializing in information technology IT. It covers the entire range of commercial software development and maintenance services. The current guide edition 5. Performance of audit-based assessments of software quality systems and consultation to organizations on the improvement of software development and maintenance processes in addition to their management. Registered IRCA auditors are required, among other things, to have experience in management and software development; they must also successfully complete an auditor's course.
Registered lead auditors are required to have a demonstrated experience in conducting and directing TickIT audits. A software process assessment is a disciplined examination of the software processes used by an organization, based on a process model. The assessment includes the identification and characterization of current practices, identifying areas of strengths and weaknesses, and the ability of current practices to control or avoid significant causes of poor software quality, cost, and schedule.
A self-assessment first-party assessment is performed internally by an organization's own personnel. A second-party assessment is performed by an external assessment team or the organization is assessed by a customer. A third-party assessment is performed by an external party or e. Software process assessments are performed in an open and collaborative environment. They are for the use of the organization to improve its software processes, and the results are confidential to the organization.
The organization being assessed must have members on the assessment team. The scope of a software process assessment can cover all the processes in the organization, a selected subset of the software processes, or a specific project.
Most of the standard-based process assessment approaches are invariably based on the concept of process maturity. When the assessment target is the organization, the results of a process assessment may differ, even on successive applications of the same method. There are two reasons for the different results. They are,. The organization being investigated must be determined. For a large company, several definitions of organization are possible and therefore the actual scope of appraisal may differ in successive assessments.
Even in what appears to be the same organization, the sample of projects selected to represent the organization may affect the scope and outcome. When the target unit of assessment is at the project level, the assessment should include all meaningful factors that contribute to the success or failure of the project.
It should not be limited by established dimensions of a given process maturity model. Here the degree of implementation and their effectiveness as substantiated by project data are assessed. Process maturity becomes relevant when an organization intends to embark on an overall long-term improvement strategy.
Software project assessments should be independent assessments in order to be objective. According to Paulk and colleagues , the CMM-based assessment approach uses a six-step cycle. Select a team - The members of the team should be professionals knowledgeable in software engineering and management. The representatives of the site to be appraised complete the standard process maturity questionnaire. The assessment team performs an analysis of the questionnaire responses and identifies the areas that warrant further exploration according to the CMM key process areas.
The assessment team conducts a site visit to gain an understanding of the software process followed by the site. The assessment team produces a list of findings that identifies the strengths and weakness of the organization's software process. The assessment team prepares a Key Process Area KPA profile analysis and presents the results to the appropriate audience. The team must consist of between four to ten team members. Team members must also meet some selection guidelines.
Assuring an acceptable level of confidence that the software will conform to functional technical requirements. Assuring an acceptable level of confidence that the software will conform to managerial scheduling and budgetary requirements.
Initiating and managing activities for the improvement and greater efficiency of software development and SQA activities. Assuring with an acceptable level of confidence that the software maintenance activities will conform to the functional technical requirements. Assuring with an acceptable level of confidence that the software maintenance activities will conform to managerial scheduling and budgetary requirements.
Initiating and managing activities to improve and increase the efficiency of software maintenance and SQA activities. This involves improving the prospects of achieving functional and managerial requirements while reducing costs. Top management executives, especially the executive directly in charge of software quality assurance. Only the managers and employees of the software testing department are occupied full time in the performance of SQA tasks. The others dedicate part of their time to quality issues, whether during fulfilment of their managerial functions or professional tasks, or as volunteers in others, most often a SQA committee, a SQA forum, or as SQA trustees.
Communicate the importance of the product and service quality in addition to customer satisfaction to employees at all levels. Assigning one of the executives such as Vice President for SQA to be in charge of software quality issues. Review proposals prepared by the SQA unit for the annual activities program and verify the proposal's potential to fulfil the objectives set for the SQA system.
Determine whether the activities program is adequate to the characteristics and scope of subcontractor services and software purchases planned for the coming year. Determine the adequacy of the manpower and other resources planned for implementation of the SQA program. These plans must be adaptable to the changes in technological as well as customer demands and competition. Review proposals for SQA adaptations such as preparation of new procedures appropriate to the new tools and SQA standards.
Preparation of training programs for veteran software development teams and newly recruited team members. Development of software quality metrics appropriate for evaluating the new tools and standards as well as the success of the training programs. Approval of the final version of the planned SQA development projects, including their schedules and budgets. General follow-up of provision of quality maintenance services to external and internal customers.
Presentation for final approval of planned SQA adaptation projects together with the corresponding budgets. Initiation of management-level discussions dedicated to special software quality events, such as severe quality failures, threats to the successful completion of projects due to severe professional staff shortages, managerial crises in the SQA unit, and so on. Review of unit performance of planned review activities; approval of project documents and project phase completion. Advice and support to project managers in resolving schedule, budget and customer relations difficulties.
Most project management responsibilities are defined in procedures and work instructions; the project manager is the person in-charge of making sure that all the team members comply with the said procedures and instructions. Close follow-up of project team staffing, including attending to recruitment, training and instruction. Software installation in remote customer sites and the execution of the software system by the customer.
The structure of SQA unit varies by type and size of the organization. The following figure shows an example of a standard structure and all the components under an SQA unit. In this chapter, we will discuss the roles and responsibilities of each sub-unit. The head of the SQA unit is responsible for all the quality assurance tasks performed by the SQA unit and its sub-units. Preparation of the recommended annual SQA activities programs and SQA systems development plans for the software development and maintenance departments.
Preparation of special and periodic reports, e. Follow-up of development and maintenance team's compliance with SQA procedures and work instructions. Monitoring customer satisfaction and maintaining contact with customer's quality assurance representatives. Transmission of training and instruction regarding adherence to and application of SQA procedures, work instructions and similar items to new and current staff. Instruction of SQA trustees regarding new and revised procedures as well as development tools and methods, among other components.
Proposal of subjects requiring preventive and corrective actions, including participation in CAB committees. External audits performed by customers who wish to evaluate the SQA system prior to accepting the organization as a supplier.
The first two classes of audits are initiated and performed by the SQA subunit, the last two by external bodies. Preparation of periodic summary reports of the status of audit findings, including recommendations for improvements. Follow-up of corrections and improvements to be carried out by the audited subcontractors and suppliers. Collection of data on the performance of subcontractors and suppliers from internal as well as external sources. Instruction of the audited teams and performance of the preparations necessary for certification audits.
Most of the consumers of SQA support services are located within the organization. They include project managers, team leaders and SQA trustees. Choice of development methodologies and tools that reflect the failure experience data accumulated by the SQA unit.
Be responsible for the development of new procedures and procedure updates, with participation in appropriate committees and forums. Follow-up on the developments and changes in SQA and software engineering standards; introduction of additional procedures and changes relevant to the organization.
Initiate updates and adaptations of procedures in response to changes in professional standards, including adoption or deletion of standards applied by the organization.
Follow-up of professional advances, solution of operational difficulties and expert analysis of failures are the immediate objectives of this SQA sub-unit. Testing quality and productivity aspects with respect to new development tools and new versions of currently used development tools. Evaluation of quality and productivity of new development and maintenance methods and method improvements.
Development of solutions to difficulties confronted in application of currently used software development tools and methods. Provision of technological support to CAB committees during analysis of software development failures and formulation of proposed solutions. SQA trustees are those members who are primarily involved in the promotion of software quality. These members provide the internal support necessary for successfully implementing SQA components.
Their tasks may vary depending upon the organizations. Support colleagues for solving the difficulties during the implementation of software quality procedures and work instructions. Promote compliance and monitor the implementation of SQA procedures and work instructions by colleagues. Initiate applications to the CAB regarding solutions to recurrent failures observed in the respective units.
Identify SQA training needs across the organization and propose appropriate training or instruction program to be conducted by the SQA unit. SQA committees can be either permanent or ad hoc. The tasks may vary considerably from organization to organization. Ad hoc committees commonly deal with specific cases of general interest such as updating a specific procedure, analysis and solution of a software failure, elaborating software metrics for a targeted process or product, updating software quality costs and data collection methods for a specific issue.
Ad hoc committees are established on a short-term per-problem basis, with members nominated by the executive responsible for software quality issues, the head of the SQA Unit, the SQA sub-units, permanent SQA committees, or any other body that initiated its formation and has an interest in the work. This body also defines the tasks of the ad hoc committee.
Arnab Chakraborty. Zach Miller. John Shea. In any software project, you can go on building the code but at some point, you need to take a break and check if the work you are doing is right, if the process you followed is correct and so on. Metrics help you in exactly that. Why are software quality metrics important? Software quality metrics are an indicator of the health of the product, process, and project. Good metrics with accurate data can help in.
Important Software Quality Metrics For any metrics to truly serve the purpose, there are 2 parts. One is the data accuracy and the second is metrics selection.
All metrics will not be suitable for all processes and projects. So the selection of the metrics needs to be done carefully. Let us now look at some very important and most commonly used Software Quality Metrics and how they are helpful in driving a better code. The first measure of the quality of any products is the number of defects found and fixed. The more the number of defects found, would be the quality of development is poor.
So the management should strive hard to improve development and do an RCA Root Cause Analysis to find why the quality is taking the hit. This is an important metric for assessing the effectiveness of a testing team. DRE is an indicator of the number of defects the tester or the testing team was able to remove from going into a production environment. As the name suggests it is the average time between two failures in a system.
Based on the AUT and expectation of business the definition of failure may vary. For any online website or mobile application crash or disconnection with the database could be the expected failure. No team can produce software that never breaks or fails, so the onus is always to increase the MTBF as much as possible, which means that in a time frame the number of times the applications fail should be reduced to an acceptable number. This again is quite self-explanatory. The mean time to recover is basically the time it takes for the developers to find a critical issue with the system, fix it and push the fix patch to production.
Hence the average time which the team needs to fix an issue in production. Important metrics especially for mobile apps and online websites. It is a measure of how often the mobile app or website crashes in any environment. It is an indicator of the quality of the code. The better the code, the longer it will be able to sustain without crashing. In recent times where the speed of delivery has taken utmost importance, the traditional methods life the SDLC and waterfall models have taken a backseat, giving way for more dynamic and fast-paced agile, scrum and lean methodologies.
This section on software quality metrics would be obsolete and incomplete if we do not look at some very important metrics in agile. Lead time is defined as the time it takes from the time of project or sprint kick-off to the completion. In an agile process, we normally pick up user stories that will be delivered at the end of the sprint. The lead time is thus defined as the time it takes to complete and deliver these user stories.
Cycle time is similar to the lead time with a difference that leads time is measured per user story, while cycle time is measured per task. For eg, if database creation is part of the user story related to client data.
Then time taken to create the database would be the cycle time, while the time taken to have the complete database ready would be the lead time. The cycle time data is used to arrive at delivery estimation timelines for future sprints.
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