Goals and questions are to be constructed in terms of their audience. These components implement international professional and managerial standards within the organization. The process will act as sensors and monitors, and we can change the process significantly in response to warning signs. In fact, for developing safety-critical software, the need to prevent and eliminate in various sectors (railways, aerospace, nuclear, automotive, etc. Product transition factors− Portability, Reusability, Interoperability. There are three development products whose size measurement is useful for predicting the effort needed for prediction. The following institutes and organizations are the main developers of SQA and software engineering standards −. The basic metrics for these tokens were, The volume of program = No. Initiating and managing activities to improve and increase the efficiency of software maintenance and SQA activities. In Software Reusability, pp. In the above diagram, each box is a table in the database, and the arrow denotes the many-to-one mapping from one table to another. A software assessment (or audit) can be of three types. Lectures by Walter Lewin. We can define more than one empirical relation on the same set. Software metrics contains many activities which include the following −. A graph-theoretic approach can be used to analyze and measure the properties of individual data structures. For a given software application, each of these elements is quantified and weighted, counting its characteristic elements, such as file references or logical fields. Team members must also meet some selection guidelines. − If the data is associated with a particular activity or time period, then it should be clearly specified in the data. At this level, the inputs and outputs of the process, constraints, and resources are identifiable. Software Reliability is an essential connect of software quality, composed with functionality, usability, performance, serviceability, capability, installability, maintainability, and documentation. 3. FTR − The number of files updated or referenced. If a program P1 has more length than program P2, then any measure m should also satisfy. Software exits in different forms throughout the software engineering process. The following indirect measures are commonly used in software engineering. A second-party assessment is performed by an external assessment team or the organization is assessed by a customer. A particular investigation method can be chosen according to the following guidelines −. The effort required to generate P is given by, $$E = V\diagup L = \frac{\mu_{1}N_{2}Nlog_{2}\mu}{2\mu_{2}}$$, Where the unit of measurement E is elementary mental discriminations needed to understand P, The other alternatives for measuring the length are −, In terms of the number of bytes of computer storage required for the program text, In terms of the number of characters in the program text. Software Reliability is the probability of failure-free software operation for a specified period of time in a specified environment. SOFTWARE REUSE • Software reuse is the use of existing software or software knowledge to build new software for an individual or an organization. Time required to get used to in using the software. 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. Object Oriented Analysis & Design Tutorial - This tutorial will help you understand the basics of object-oriented analysis and design along with its associated terminologies. Identify areas of improvement 3. Quality models have been developed for the measurement of quality of the product without which productivity is meaningless. Validating the measurement of software system involves two steps −. Fix quality or the number of defective fixes is another important quality metric for the maintenance phase. Software Functional Quality − It reflects how well it satisfies a given design, based on the functional requirements or specifications. Customer satisfaction is often measured by customer survey data through the five-point scale −, Satisfaction with the overall quality of the product and its specific dimensions is usually obtained through various methods of customer surveys. Here the degree of implementation and their effectiveness as substantiated by project data are assessed. Usability Testing Process: Previous Page Print Page. These quality models can be combined with productivity model for measuring the correct productivity. Hence, measurement plays a significant role in software engineering. It includes the following −. It is the mapping from the empirical world to the formal relational world. The improvement in the process or products can be performed only when the project has clearly defined goals for processes and products. The pattern of defect backlog overtime. The tasks involved include −, Development of SQA information systems for software development and maintenance units for, processing of, for example, periodic reports, lists, exception reports and queries, Development of SQA information systems facilitating the SQA unit’s processing of information delivered by software development and maintenance units including estimates of software quality metrics and software quality costs, Development and maintenance of the organization’s SQA Internet /Intranet site. Let's explore this in detail. are copied and adapted to fit new requirements. The representational condition asserts that a measurement mapping (M) must map entities into numbers, and empirical relations into numerical relations in such a way that the empirical relations preserve and are preserved by numerical relations. It is mainly of 5 types −. It is an important area of software engineering research that promises significant improvements in software productivity and quality. 1. They are −. • Where feasible, software engineers should avoid re-developing software – software engineers should also make their designs reusable. Several models of software quality factors and their categorization have been suggested over the years. This tutorial provides a complete overview of Software Quality Management and describes the various steps involved in the process. They will make you ♥ Physics. It is the time between failures. Assuring an acceptable level of confidence that the software will conform to functional technical requirements. The first category of the factors is of those that can be measured directly such as the number of logical errors, and the second category clubs those factors which can be measured only indirectly. The length of the program can be measured by counting the lines of code. The success in the software measurement lies in the quality of the data collected and analyzed. The classic model of software quality factors, suggested by McCall, consists of 11 factors (McCall et al., 1977). Basically, a three-level structure of management exists in software development organizations −, Following are the responsibilities of the top management in ensuring Software Quality −, Assure the quality of the company’s software products and software maintenance services, Communicate the importance of the product and service quality in addition to customer satisfaction to employees at all levels, Assure satisfactory functioning and full compliance with customer requirements, Ensure that quality objectives are established for the organization’s SQA system and that its objectives are accomplished, Initiate planning and oversee implementation of changes necessary to adapt the SQA system to major internal as well as external changes related to the organization’s clientele, competition, and technology, Intervene directly to support resolution of crisis situations and minimize damages, Ensure the availability of resources required by SQA systems, The following steps can be taken by the top management to fulfill its responsibilities −. It contains the customer’s perspective towards the problem space of the software, which includes the non-defect oriented problems together with the defect problems. For example, a survey of completed projects can reveal that a software written in a particular language has fewer faults than a software written in other languages. ILF − The number of internal log files. These attributes describe not only the code but also the other documents that support the development effort. Quality software refers to a software which is reasonably bug or defect free, is delivered in time and within the specified budget, meets the requirements and/or expectations, and is maintainable. Are they consistent? A software process assessment is a disciplined examination of the software processes used by an organization, based on a process model. If the defect backlog is large at the end of the development cycle and a lot of fixes have yet to be integrated into the system, the stability of the system (hence its quality) will be affected. After signing the software development contract with an organization or an internal department of the same organization, a development plan of the project and its integrated quality assurance activities are prepared. This factor deals with the software system security, that is, to prevent access to unauthorized persons, also to distinguish between the group of people to be given read as well as write permit. Management of software development, maintenance and the specific SQA units, A software development and maintenance project team, Organization of SQA systems, infrastructure and requirements, Methodologies for carrying out software development and maintenance projects, Assuring the supplier’s software quality and assessing its software process capability. Portability requirements tend to the adaptation of a software system to other environments consisting of different hardware, different operating systems, and so forth. Compute value adjustment factor (VAF) based on 14 general system characteristics (GSC). It identifies the software as a system with many components interacting with each other. What is Software Reusability? The accuracy of a measurement depends on the measuring instrument as well as on the definition of the measurement. Data structure − It is the organization of the data elements in the form of lists, queue, stacks, or other well-defined structures along with algorithm for creating, modifying, or deleting them. The organization being assessed must have members on the assessment team. Publication of the TickIT Guide, which supports the software industry’s efforts to spread ISO 9001 certification. Software project assessments should be independent assessments in order to be objective. Let's explore this in detail. Rate each component as low, average, or high. • Where feasible, software engineers should avoid re-developing software – software engineers should also make their designs reusable. 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. They may also enable future projects to make use of a given module or a group of modules of the currently developed software. These factors are as follows −. Component Reusability Watch more Videos at https://www.tutorialspoint.com/videotutorials/index.htm Lecture By: Mr. Arnab Chakraborty, Tutorials Point … 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. in order to understand, assess, manage, engineer, learn, improve, etc. This difference is due to the following reasons. This model can assess many different attributes of development including the use of tools, standard practices and more. Definition of Software Reusability: Software exits in different forms throughout the software engineering process. The 11 factors are grouped into three categories – product operation, product revision, and product transition factors. Typical goals are expressed in terms of productivity, quality, risk, customer satisfaction, etc. J. Sametinger: Software Engineering with Reusable Components (Habilitationsschrift), Springer-Verlag, ISBN 3-540-62695-6, 1997. The user should not be able to login with correct username and incorrect password. He proposed three internal program attributes such as length, vocabulary, and volume that reflect different views of size. When we solve a problem we try to apply the solution to similar problems because that makes our work easy and simple. Software metrics is a standard of measure that contains many activities, which involves some degree of measurement. In the software industry, the developers will never declare that the software is free of defects, unlike other industrial product manufacturers usually do. It is a research technique where you identify the key factors that may affect the outcome of an activity and then document the activity: its inputs, constraints, resources, and outputs. Hence, a prediction system consists of a mathematical model together with a set of prediction procedures for determining the unknown parameters and interpreting the results. He began by defining a program P as a collection of tokens, classified by operators or operands. In an example library database system, the file of books in the library. In an example library database system, determine what books are currently checked out to a patron. A second measure which is also a direct and valid measure of the affecting factor should be used to validate. The classes will not be ordered. Measurement is a direct quantification whereas calculation is an indirect one where we combine different measurements using some formulae. It ensures that developed software meets and complies with the defined or standardized quality specifications. Here, the user has to give a number according to its importance. Assuring with an acceptable level of confidence that the software maintenance activities will conform to the functional technical requirements. Data-flow structure − It is the behavior of the data as it interacts with the program. The pattern of valid defect arrivals when problem determination is done on the reported problems. The quality assurance organizational framework that operates within the organizational structure includes the following participants −, Top management executives, especially the executive directly in charge of software quality assurance, Software development and maintenance department managers, Project managers and team leaders of development and maintenance projects, SQA professionals and interested practitioners −. Invisible Product Difficult to detect defects by sight, Visible Product Effective detection of defects by sight, Nature of development and production process, can detect defects in all of the following phases. Thus, the process change can affect the organization and the project as well as the process. Rather than checking for quality after completion, SQA processes test for quality in each phase of development, until the software is complete. Select a team - The members of the team should be professionals knowledgeable in software engineering and management. What percentage of the information is entered online? Software Quality Management is a process that ensures the required level of software quality is achieved when it reaches the users, so that they are satisfied by its performance. $\frac{Number \: of \: fixes \: that\: exceeded \: the \:response \:time\:criteria\:by\:ceverity\:level}{Number \: of \: fixes \: delivered \: in \:a \:specified \:time} \times 100\%$. GQM helps to understand the need for measuring the attribute, and process maturity suggests whether we are capable of measuring it in a meaningful way. In the real world, even though we are thinking of measuring the things, actually we are measuring the attributes of those things. The team must consist of between four to ten team members. A rigorous approach will be necessary for measuring the attributes of a software product. This investigation mainly contains the following 4 principles. RET − The number of user-recognizable data elements in an ILF or ELF. The process involves quality assurance, quality planning, and quality control. Architectural Design - The architectural design is the highest abstract version of the system. They are. Product metrics describe the characteristics of the product such as size, complexity, design features, performance, and quality level. This assures that the project commitments have been clearly defined considering the resources required, the schedule and budget; and the development and quality plans have been correctly determined. The mappings define the constraints that preserve the logical consistency of the data. The different models proposed are −. ISO technical committees prepare the International Standards. Project methodology, development tools, etc. They determine the maximum allowed failure rate of the software system, and can refer to the entire system or to one or more of its separate functions. Halstead’s software science attempted to capture different attributes of a program. It involves product-focused action. Higher defect rates found during testing is an indicator that the software has experienced higher error injection during its development process, unless the higher testing defect rate is due to an extraordinary testing effort. This database will store the details of different employees working in different departments of an organization. Empirical relations in the real world can be mapped to a formal mathematical world. Reusability • Software development process called frameworks that promotes reuse. When the assessment target is the organization, the results of a process assessment may differ, even on successive applications of the same method. Some models such as reliability models do not influence the outcome, since reliability measured as mean time to failure cannot be evaluated until the software is ready for use in the field. Different code libraries classes should be generic enough to use easily in different application modules. There is only one possible measurement mapping, namely the actual count. Survey is the retrospective study of a situation to document relationships and outcomes. Reuse Practiced by Software Engineers 1. The data collected can be considered as a good data, if it can produce the answers for the following questions −. It is always done after an event has occurred. Normally, a software is developed for a contract negotiated with a customer or for an internal order to develop a firmware to be embedded within a hardware product. The standards for coding and documenting the software system. The size of the product tells us about the effort needed to create it. Tutorial, software reusability on Amazon.com. SOFTWARE REUSE • Software reuse is the use of existing software or software knowledge to build new software for an individual or an organization. If replication is not possible at higher levels, then experiment is not possible. Using it in the format of a trend chart, this metric can provide meaningful information for managing the maintenance process. Actual data collection takes place during many phases of development. A state variable which is the factor that can characterize the project and can also influence the evaluation results is used to distinguish the control situation from the experimental one in the formal experiment. It measures the functionality from the user’s point of view, that is, on the basis of what the user requests and receives in return. The empirical relation system consists of classes that are ordered with respect to the attribute. SQA unit performs the following tasks for internal SQA audits, Preparation of annual programs for internal SQA audits, Follow-up of corrections and improvements to be carried out by the audited teams and other units, Preparation of periodic summary reports of the status of audit findings, including recommendations for improvements, SQA unit performs the following tasks for audits of subcontractors and suppliers −, Preparation of the annual program for SQA audits of subcontractors and suppliers, Performance of SQA audits of subcontractors and suppliers, 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, Periodic evaluation of the organization’s certified subcontractors’ and suppliers’ SQA systems based on audit reports and information collected from other internal and external sources. Software reuse is still an emerging discipline. Example: The customers of this software are those who have no knowledge about the tools. Product transition factors − Portability, Reusability, Interoperability. 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). Manufacturing − In this phase, QA procedures are applied to detect failures of products themselves. A particular measurement will be useful only if it helps to understand the process or one of its resultant products. According to McCall’s model, three software quality factors are included in the product transition category that deals with the adaptation of software to other environments and its interaction with other software systems. There are two reasons for the different results. Since, there can be many relations on a given set, the representational condition also has implications for each of these relations. Software reliability testing a testing technique that relates to testing a software's ability to function given environmental conditions consistently that helps uncover issues in the software design and functionality. SQA trustees are those members who are primarily involved in the promotion of software quality. These characteristics of software such as complexity and invisibility make the development of software quality assurance methodology and its successful implementation a highly professional challenge. If we cannot differentiate control from experiment, case study technique will be a preferred one. It is especially useful to monitor subsequent releases of a product in the same development organization. Software Reliability is hard to achieve because the complexity of software turn to be high. However, formal experiment can investigate the situations in which the claims are generally true. Inheritance helps in the software re-usability by using the existing components of the software to create new component. With SQA, the software development process moves into the next phase only once the current/previous phase complies with the required quality standards. DET − The number of user-recognizable fields. Are they associated with a particular activity or time period? The degree of accuracy acceptable for validation depends upon whether the prediction system is deterministic or stochastic as well as the person doing the assessment. Local indirect flow − If the invoked module returns information that is subsequently passed to a second invoked module. Its components are divided into the following sub-classes: Reviews, Expert opinions, and Software testing. Software reusability is the use of engineering knowledge or artifacts from existing software components to build a new system. FPC = UFC * (0.65+(sum(GSC) * .01)), Complexity is a separate component of size. There are many software measures to capture the value of an attribute. The upper branches hold important high level quality factors such as reliability and usability. The different internal product attributes are size, effort, cost, specification, length, functionality, modularity, reuse, redundancy, and syntactic correctness. It measures the problems that customers encounter when using the product. Reuse Practiced by Software … How many ILFs are updated by online transaction? In this Informatica tutorial for beginners, you will learn Informatica from the basics to get a clear idea of how Informatica ETL tool works. Some of the mapping or rating technique used to map these empirical relations to the mathematical world is follows −. For checking whether the project is on track, users and developers can rely on the measurement-based chart and graph. How many communication facilities are there to aid in the transfer or exchange of information with the application or system? The assessment team produces a list of findings that identifies the strengths and weakness of the organization's software process. The most intuitive reuse is in the reality of “plug-and-play” just … Hence, to validate a prediction system formally, we must decide how stochastic it is, then compare the performance of the prediction system with known data. Software Structural Quality − It deals with the handling of non-functional requirements that support the delivery of the functional requirements, such as robustness or maintainability, and the degree to which the software was produced correctly. They include −. Attributes are mostly defined by numbers or symbols. Hence, the main engineering tasks involve the following −, 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, Development of methods for measuring software quality and team productivity, Provision of technological support to CAB committees during analysis of software development failures and formulation of proposed solutions, SQA information systems are meant to facilitate and improve the functioning of SQA systems. A software requirement can be of 3 types: Functional requirements; Non-functional requirements; Domain requirements ; Functional Requirements: These are the requirements that the end user specifically demands as basic facilities that the system should offer. Following are some of the internal attributes that can be measured directly for a process −, The duration of the process or one of its activities, The effort associated with the process or one of its activities, The number of incidents of a specified type arising during the process or one of its activities. To achieve each of these, the objective should be expressed formally in terms of the hypothesis, and the analysis must address the hypothesis directly. The investigation must be designed to explore the truth of a theory. The required accuracy of output that can be negatively affected by inaccurate data or inaccurate calculations. Weigh each GSC on a scale of 0 to 5 based on whether it has no influence to strong influence. Usability requirements deal with the staff resources needed to train a new employee and to operate the software system. [Biggerstaff 1989] T. J. Biggerstaff: Design Recovery for Maintenance and Reuse. It is a measurement mapping that preserves ordering, the size of intervals between the entities and the ratio between the entities. To boost the decision of a particular investigation technique, the goal of the research should be expressed as a hypothesis we want to test. Product revision factors− Maintainability, Flexibility, Testability. The results of the case study or survey can normally be applicable only to a particular organization. Several national and international standards institutes, professional and industry-oriented organizations have been involved in the development of SQA standards. For a large company, several definitions of organization are possible and therefore the actual scope of appraisal may differ in successive assessments. Measurement of structural properties of a software is important for estimating the development effort as well as for the maintenance of the product. EO − The number of external output. It places the elements in a classification scheme. These are elementary processes in which derived data passes across the boundary from outside to inside. However, software packages allow millions of operational possibilities. These are the measurements that can be measured without the involvement of any other entity or attribute. If the data is from a normal distribution and there are two groups to compare then, the student’s t test can be used for analysis. Project metrics − This metrics describe the project characteristics and execution. Many sets of data are distributed normally as shown in the following graph. 3. Increase return on investment (ROI) 2. i.e., it measures code quality per unit. Validating a software measurement system is the process of ensuring that the measure is a proper numerical characterization of the claimed attribute by showing that the representation condition is satisfied. These factors are as follows −. The Capacity Maturity Model (CMM) developed by the Software Engineering Institute (SEI), Carnegie Mellon University, and ISO/IEC Std 15504 are the examples of this approach. To help the measurement process, the model of the mapping should also be supplemented with a model of the mapping domain. It includes predefined intermediate results, log files, and also the automatic diagnostics performed by the software system prior to starting the system, to find out whether all components of the system are in working order and to obtain a report about the detected faults. Example − ISO 9000-3 and the Capability Maturity Model (CMM), These focus on the methodologies for implementing the software development and maintenance projects. These tasks can be classified into the following categories −, Preparation of the proposed annual activity program and budget for the unit, Planning and updating the organization’s software quality management system, Preparation of the recommended annual SQA activities programs and SQA systems development plans for the software development and maintenance departments, Monitoring implementation of the SQA activity program, Nomination of team members, SQA committee members and SQA trustees, Preparation of special and periodic reports, e.g., the status of software quality issues within the organization and monthly performance reports, SQA tasks related to the project life cycle sub-unit may be classified into two groups −, “Pure” managerial follow-up and approval tasks (project life cycle control tasks), “Hands-on” or active participation in project team SQA activities, where professional contributions are required (participation tasks), Follow-up of development and maintenance team's compliance with SQA procedures and work instructions, Approval or recommendation of software products according to the relevant procedures, Monitoring delivery of software maintenance services to internal and external customers, Monitoring customer satisfaction and maintaining contact with customer's quality assurance representatives, SQA systems employ a variety of infrastructure components to operate smoothly, namely −, More specifically, the SQA sub-unit’s tasks regarding these components include −, Publication of updated versions of procedures, work instructions, templates, checklists, and so forth, together with their circulation in hard copy and/or by electronic means, 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, Monitoring and supporting implementation of new and revised SQA procedures, Follow-up of staff certification activities, Proposal of subjects requiring preventive and corrective actions, including participation in CAB committees, Follow-up of configuration management activities, including participation in CCA committees, Follow-up of compliance with documentation procedures and work instructions, The types of SQA audits carried out in or by software organizations can be classified as follows −, Audits of subcontractors and suppliers to evaluate their SQA systems, External audits performed by certification bodies, External audits performed by customers who wish to evaluate the SQA system prior to accepting the organization as a supplier. The project managers often turn the predictions into targets for completion. Validation is performed by correlating one measure with another. Jean-Louis Boulanger, in Certifiable Software Applications 1, 2016. This factor deals with the use of software modules originally designed for one project in a new software project currently being developed. Similarly, linear regression can be used to generate an equation to describe the relationship between the variables. Based on the five-point-scale data, several metrics with slight variations can be constructed and used, depending on the purpose of analysis. OOA/D, University of Educatoin Okara 3 4. The numbers represent ranking only. Registered lead auditors are required to have a demonstrated experience in conducting and directing TickIT audits. At this level, the measures from activities are used to improve the process by removing and adding process activities and changing the process structure dynamically in response to measurement feedback. Was the application specifically designed, developed, and supported to be installed at multiple sites for multiple organizations? They are as follows −. Dr. Edward Lavieri. Data collection planning must begin when project planning begins. Software reusability is generally considered a way to solve the software development crisis. Backlog Management Index (BMI) is used to manage the backlog of open and unresolved problems. The reuse of software is expected to save development resources, shorten the development period, and provide higher quality modules. We will discuss one such method ─ the Albrecht’s Function Point method ─ in the next chapter. It measures any software product that can be modeled as an algorithm. These include adapting the current software to additional circumstances and customers without changing the software. Our client, an enterprise software company and one of the leaders in travel domain, was maintaining 5 websites. The main objective of these components, which is applied throughout the entire organization, is to eliminate or at least reduce the rate of errors, based on the organization’s accumulated SQA experience. They include project managers, team leaders and SQA trustees. Cost and effort estimation models have been proposed to predict the project cost during early phases in the software life cycle. The structure of software has three parts. The investigation’s design must be considered while choosing the analysis techniques. During these period, resources such as staff availability, professional capabilities may get changed. The McCall factor model provides a practical, up-to-date method for classifying software requirements (Pressman, 2000). For validating a measurement system, we need both a formal model that describes entities and a numerical mapping that preserves the attribute that we are measuring. In addition to testing, it tracks the defects at all phases of the development cycle, including the design reviews, code inspections, and formal verifications before testing. After collecting relevant data, we have to analyze it in an appropriate way. The flow of data carries a batch of data as a whole from one subsystem to another. TickIT is, additionally, specializing in information technology (IT). A model should also specify how these entities are related to the attributes and how the characteristics relate. The quality of any measurement program is clearly dependent on careful data collection. 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. Product metrics − Describes the characteristics of the product such as size, complexity, design features, performance, and quality level. For transactions (EI, EO, and EQ), the rating is based on FTR and DET. They are −. For the unary relation ‘is tall’, we might have the numerical relation. According to McCall’s model, three software quality factors are included in the product revision category. External attributes are those that can be measured only with respect to its relation with the environment. 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. They are specification, design, and code. The systematic reuse of these components as building blocks to create new systems. Examples include the number of software developers, the staffing pattern over the life cycle of the software, cost, schedule, and productivity. Complexity of a problem − It is the amount of resources required for an optimal solution to the problem. found that a count of objects and methods led to more accurate productivity estimates than those using lines of code. It is called early defect removal when used for the front-end and phase effectiveness for specific phases. As a live example, we recently explored Component Reusability for a client partner to bring in cost and time savings. Every measurement action must be motivated by a particular goal or need that is clearly defined and easily understandable. Software specifications, designs, tests cases, data, prototypes, plans, documentation, frameworks, and templates are all candidates for reuse. For example: If most of the data is present on the left-hand side of the mean, then we can say that the distribution is skewed to the left. Often the output from one process directly forms the input to the next. The Function Point measure originally conceived by Albrecht received increased popularity with the inception of the International Function Point Users Group (IFPUG) in 1986. Product transition factors − Portability, Reusability, Interoperability. The input measures can be the size and volatility of the requirements. Suppose we are currently using FORTRAN which we want to replace by Ada. 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). Corrective Maintenance - This includes modifications and updations done in order to correct or fix problems, which are either di… The plans are then revised to reflect the changes that occurred in the interim. In an example library database system, the file that contains transactions in the library's billing system. Software reusability includes the reuse of any software artifacts in various formats. At least, one team member must be from the organization being assessed, and all team members must complete the SEI's Introduction to the CMM course (or its equivalent) and the SEI's CBA IPI team training course. The 11 factors are grouped into three categories – product operation, product revision, and product transition factors. Process metrics − These characteristics can be used to improve the development and maintenance activities of the software. In-process quality metrics deals with the tracking of defect arrival during formal machine testing for some organizations. At a given maturity level, we can collect the measurements for that level and all levels below it. The McCall factor model provides a practical, up-to-date method for classifying software requirements (Pressman, 2000). Software reuse is a good cost-efficient and time-saving development way. Here, the user has to give a number by comparing the different options. How are distributed data and processing functions handled? Safety-critical software is called reliable software. Percent of completely satisfied customers, Defect arrival pattern during machine testing, We fail to set measurable targets for our software products, We fail to understand and quantify the component cost of software projects, We do not quantify or predict the quality of the products we produce, To understand what is happening during development and maintenance, To control what is happening in the project, Duration of testing purpose by elapsed time, Number of defects discovered during the testing process by counting defects, The time a programmer spends on a program, Maintaining the control over the variable, Identifying the level of maturity that the organization has reached, IEEE (Institute of Electrical and Electronics Engineers) Computer Society, ISO (International Organization for Standardization), ANSI (American National Standards Institute), IEC (International Electro Technical Commission), Understanding and meeting the requirements, Need to consider the processes in terms of added value, Obtain the results of process performance and effectiveness, Continual improvement of processes based on objective measurement, Feedback from the review of the draft findings with the assessment participants, Administer the CMMI Appraisal Questionnaire, Prepare the presentation of draft findings, Consolidate, rate, and prepare the final findings, Participation in project joint committees, Review and approval of deviations from specifications, Consultation with project managers and team leaders, Participation in SQA committees and forums, Preparation and updating of project development and quality plans, Software testing, including customer acceptance tests, Software acceptance tests of subcontractors’ software products, Supporting quality devices (templates, checklists), Staff training, instruction and certification. 17-49, Ellis-Horwood, New York, 1994. The term "usability" in the context of creating software represents an approach that puts the user, instead of the system, at the center of the process. Each can be decomposed into different measurable size, functionality, time, money, etc. The important elements of fix responsiveness are customer expectations, the agreed-to fix time, and the ability to meet one's commitment to the customer. It involves experimentation and hypothesis testing. 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. Each of these relationships can be expressed as a hypothesis and a formal experiment can be designed to test the degree to which the relationships hold. 36-49. The major reason for measuring internal product attributes is that, it will help monitor and control the products during development. Usually the longer the latency, the more will be the customers that get affected. − Data can be considered as consistent, if it doesn’t show a major difference from one measuring device to another. Correlation analysis uses statistical methods to confirm whether there is a true relationship between two attributes. If ‘m’ is a structural measure defined in terms of the flow graph model, and if program A is structurally more complex than program B, then the measure m(A) should be greater than m(B). These members provide the internal support necessary for successfully implementing SQA components. Data structure measures can then be defined hierarchically in terms of values for the primes and values associated with the various operations. Many believe software reusability provides the key to tremendous benefits and saving in software development product. Reliability requirements deal with service failure. Software reliability is a term to be avoided, though it is used widely and there are suggestions that the term reliable software could be used instead. These factors are as follows −. A clear understanding of goals can be used to generate suggested metrics for a given project in the context of a process maturity framework. They are as follows −, These requirements deal with the correctness of the output of the software system. 3. Draft of the International Standards adopted by the technical committees is circulated to the member bodies for voting. The measurement is made by counting the number of elements in the entity set. 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. Prediction systems are used to predict some attribute of a future entity involving a mathematical model with associated prediction procedures. They are as follows −, These requirements deal with the correctness of the output of the software system. They are for the use of the organization to improve its software processes, and the results are confidential to the organization. For example − How often does this program fail? These external audits assess achievements in the development of SQA systems and their implementation. The standard set of measurements and reporting methods are especially important when the software is embedded in a product where the customers are not usually well-versed in software terminology. A scatter plot represents the relationship between two variables. Data collected can be distilled into simple charts and graphs so that the managers can understand the progress and problem of the development. • Example of software reuse is software library . It is the assignment of a number to a characteristic of an object or event, which can be compared with other objects or events. Software quality metrics are a subset of software metrics that focus on the quality aspects of the product, process, and project. Testability requirements deal with the testing of the software system as well as with its operation. Case studies or surveys can be used to conform the effectiveness and utility of the conventional wisdom and many other standards, methods, or tools in a single organization. The required accuracy of output that can be negatively affected by inaccurate data or inaccurate calculations. To help generate the goals, questions, and metrics, Basili & Rombach provided a series of templates. Hence, it is more powerful than the nominal scale and the ordinal scale. It appears in many difierent forms from ad-hoc reuse to systematic reuse, and from white-box reuse to black-box reuse. Assuring the supplier’s software quality and assessing its software process capability Assuring the quality of a specific software project. Measurement is the action of measuring something. Software Quality Assurance (SQA) is a set of activities for ensuring quality in software engineering processes. The various factors, which influence the software, are termed as software factors. Reliability – It is an attribute of software quality. It differs from hardware reliability in that it reflects the design perfection, rather than manufacturing perfection. As per the design pattern reference book Design Patterns - Elements of Reusable Object-Oriented Software, there are 23 design patterns which can be classified in three categories: Creational, Structural and Behavioral patterns. Reusability. Following points prove the efficiency of these techniques to answer a variety of questions. The representatives of the site to be appraised complete the standard process maturity questionnaire. If an attribute is measurable on an interval scale, and M and M’ are mappings that satisfy the representation condition, then we can always find two numbers a and b such that, This is the most useful scale of measurement. DOI: 10.1007/978-3-662-03345-6. For example −. The different external attributes of a process are cost, controllability, effectiveness, quality and stability. They determine the maximum allowed failure rate of the software system, and can refer to the entire system or to one or more of its separate functions. Based on the following table, an EI that references 2 files and 10 data elements would be ranked as average. There are three major items to consider for choosing the analysis technique. For example, the assessment team must be led by an authorized SEI Lead Assessor. For example: The total number of failures experienced by a user, the length of time it takes to search the database and retrieve information. A box plot can represent the summary of the range of a set of data. Theses graphs are called control-flow graph or directed graph. Naturally, due to their characteristics, many SQA standards in this class can serve as software engineering standards and vice versa. The organization being investigated must be determined. For example, the firmware of the production machinery and testing equipment interfaces with the production control software. Formally it can be defined as, the process by which numbers or symbols are assigned to attributes of entities in the real world, in such a way as to describe them according to clearly defined rules. Defects in the product detected in the first period of manufacturing can usually be corrected by a change in the product’s design or materials or in the production tools, in a way that eliminates such defects in products manufactured in future. The various standards may be classified into two main groups: quality management standards and project process standards. The different external attributes are productivity, experience, quality, usability, reliability, comfort etc. Here, the users will be given a statement upon which they have to agree or disagree. − A data can be considered correct, if it was collected according to the exact rules of the definition of the metric. At this level, the designers get the idea of proposed solution domain. High-level Design- The high-level design breaks the ‘single entity-multiple component’ concept of architectural design into less-abstracted view of sub-systems and modules and depicts their interaction with each ot… Interoperability requirements focus on creating interfaces with other software systems or with other equipment firmware. 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. Hence, the data should also be possible to replicate easily. Software Reliability is also an important factor affecting system reliability. Refined data − Refined data results from extracting essential data elements from the raw data for deriving values for attributes. Their main objectives are to initiate and support the implementation of SQA components, detect deviations from SQA procedures and methodology, and suggest improvements. EI − The number of external inputs. Yourdon Press Computing Series, ISBN 0-13-327859-X, Prentice Hall, 1997. Even in what appears to be the same organization, the sample of projects selected to represent the organization may affect the scope and outcome. For these measurements, the atomic objects are to be defined for different types of diagrams and symbols. • Software reuse is also called as “Code Reuse”. According to McCall’s model, product operation category includes five software quality factors, which deal with the requirements that directly affect the daily operation of the software. ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies. Software quality metrics can be further divided into three categories −. These models are usually constructed in a tree-like fashion. Also the absence of a part in an industrial product can be easily detected in the product. The population or sample can be described by the measures of central tendency such as mean, median, and mode and measures of dispersion such as variance and standard deviation. Locally, the amount of structure in each data item will be measured. Examples of stochastic prediction systems are systems such as software cost estimation, effort estimation, schedule estimation, etc. Perspective − Examine the (cost, effectiveness, correctness, defects, changes, product measures, etc.) An attribute is a feature or property of an entity such as the height of a person, cost of a journey, etc.
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