o In this session, you will learn to: Identify various dimensions of quality processes Define extension mechanisms of UML
o The purpose of quality processes is to examine the quality of software models and products developed during the software development process.o Quality process includes: Quality of the software development process that is used to develop the software system. Quality of the software models that are used for the software development process. Quality of the software product obtained at the end of the software development process. Quality of the quality process itself.
o The dimensions that need to be considered to produce a quality product are: Technology: Describes the tools required for the software development process and the output generated. Methodology: Describes the sequence of actions that need to be performed during the software development process to generate output. Sociology: Describes the human resources, environmental conditions, and skills required for the software development process.
o Quality checks that you need to apply to ensure the quality of software products are: Data quality Code quality Model or architecture quality Process quality Management quality Quality environment
o Which of the following quality checks ensures that the series of activities and tasks performed to develop software products are correct? 1. Code quality 2. Process quality 3. Management quality 4. Model or architectural qualityo Answer: Process quality
o Modeling enhances the quality of software products because it enables you to understand the existing software system and create the desired software system.o To improve the quality of software products, you need to analyze the effect of UML on the following quality aspects: Quality of visualization: Refers to the quality of visual representation of the artifacts, diagrams, and models. Quality of specification: Refers to the quality of the specifications that provide detailed description of UML artifacts and diagrams. Quality of construction: Refers to the quality of the code generated from the UML models. Quality of documentation: Refers to the quality of the document that provides guidelines for creating UML artifacts and diagrams in software models.
o To verify and validate the quality of the software models, you need to apply quality assurance techniques.o The quality assurance techniques check the following: Syntax: To ensure that the software models are syntactically correct. Semantics: To ensure that the software models represent their intended meaning and their representation is consistent across the project. Aesthetics: To ensure that the software models are symmetric and complete.
o Quality process metamodel: Defines a language for representing another model. Enables you to understand and describe the elements of a quality process that are applicable to software development process. Depicts the rules that describe how the elements of a quality process are connected and related to each other.
o UML Notations for Elements of Quality Process: Notation Quality Process Element Process-component Start of process-component End of process-component Role Activity Flow of activity Task Output Iteration
o Process-Component: A process-component is a set of activities, tasks, roles, and output of the quality process. The people who perform roles of a process-components execute activities and tasks to produce desired output. For example: Requirement modeling, system designing, and testing can be process-components in an UML-based project.
o Which of the following process-components indicates the execution of a sequence of process-components with varying intensity? 1. Iteration 2. Output 3. Task 4. Activityo Answer: Iteration
o UML provides several extension mechanisms that enable developers to modify the software models without changing the existing notations.o UML also provides additional modeling constructs that represent flow of events in a software system.
o UML can be tailored according to a particular application domain.o The three types of extension elements provided by UML are: Stereotypes: Extends the vocabulary of UML Constraints: Extends the semantics of building blocks of UML Tagged values: Extends the properties of building blocks of UMLo Stereotypes: Represent model elements for which UML does not have a specific notation. Enable you to distinguish between representation of two similar elements in a UML diagram. Are represented as a text string enclosed within guillemets (<< >>).
o Constraints: Represent restrictions and relationships that cannot be represented using UML notations. Represent global conditions or conditions that affect several elements of UML diagrams. Are enclosed within braces in UML diagrams.o Tagged values: Store project management related information, such as date of creating an element and the development and test status of the element. Store information about stereotyped model elements. Can be attached to any model element. Are represented as a pair of strings within braces.
o While modeling a software system using UML, you need to consider the concurrency and synchronization of the events.o UML provides two standard stereotypes that apply to active classes for modeling the concurrent flow of events in a software system: process: Represents that a process can execute concurrently with other processes. thread: Represents that a thread can execute concurrently with other threads within the same process.
o Steps to model multiple flows of events in UML class and interaction diagrams are: 1. Identify the concurrent flow of events in a software system. 2. Identify active objects based on the concurrent flow of events. 3. Group the common set of active objects into an active class. 4. Balance the distribution of responsibilities among the active classes. 5. Ensure that each active class is both tightly cohesive and loosely coupled. 6. Create class diagrams to represent static semantics of the system. 7. Create interaction diagrams to represent dynamic semantics of the system. 8. Apply the various types of communication methods among objects. 9. Attach constraints to ensure synchronization among objects.
o History state enables a sequential composite state to remember the last sub-state that was active before the composite state.o UML provides two types of history states: Shallow: Enables an application to remember and reactivate a state that is at the same nesting depth as the history state. Deep: Enables an application to remember and reactivate a state that is nested at some depth within the composite state.o System designers use comments in UML diagrams to provide additional information to the programmers about a model element or a group of model elements.o You depict a comment in UML diagrams by using a note symbol.
o In this session, you learned that: The quality process is implemented between iterations and increments of the software development process to ensure the quality of software products. The quality process checks the quality of output after each phase of software development process. The software development and quality processes are together known as the quality software process. The quality process consists of three dimensions: Technology: Describes what the software development process produces. Methodology: Describes how the software development process produces the software. Sociology: Describes who produces the software in the software development process.
The activities of each dimension of quality process occur simultaneously. UML affects the quality of visualization, specification, construction, and documentation of software models. To ensure the quality of software models, you need to check their syntax, semantics, and aesthetics. The quality process metamodel depicts the elements of quality process and their relationships. The elements of quality process are process-components, roles, activities, tasks, outputs, and iterations. To modify UML, you can use the extension elements: stereotypes, constraints, and tagged values. UML also provides additional modeling constructs, such as history states, notes, and comments.