Traditional Component Design for WebApp Functional Components

Component-Based Software Engineering (CBSE)

• CBSE involves designing and constructing WebApp functional components identical to software components for conventional software.
• Traditional components focus on functions and data structures, whereas OO components encapsulate data.

Traditional Component Design

• Design of processing logic is governed by the principles of algorithm design and structured programming.
• Design of data structures is defined by the data model developed for the system.
• Design of interfaces is governed by the collaborations that a component must effect.

Component-Based Software Engineering (CBSE) Benefits

• Reduced lead time: building complete applications from a pool of existing components is faster.
• Greater return on investment (ROI): purchasing components can be more cost-effective than redeveloping the same functionality in-house.
• Leveraged costs of developing components: reusing components in multiple applications allows costs to be spread over multiple projects.
• Enhanced quality: using existing components can improve overall system quality.

Component Level

• Component-level design defines the data structure, algorithm, interface, characteristics, and communication to each software component.
• A complete set of software components is defined during architectural design.

Component Definition

• According to the Object Management Group (OMG) Unified Modeling Language Specification, a component is a modular, deployable, and replaceable part of a system that encapsulates implementation and exposes a set of interfaces.
• An object-oriented view of a component contains a set of collaborating classes.
• A traditional view of a component contains processing logic, internal data structures, and an interface.
• A process-related view of a component involves building systems out of reusable software components or design patterns selected from a catalogue.

Component Diagram

• A component diagram breaks down the actual system under development into various high levels of functionality.
• Components are reused and tested in many different applications.
• Maintenance of component-based applications involves replacing obsolete components with new or enhanced components.

CBSE Risks

• Component selection risks: predicting component behavior for black-box components or poor mapping of user requirements to component architectural design.
• Component integration risks: lack of interoperability standards between components.
• Quality risks: unknown design assumptions made for components, affecting system safety, performance, and reliability.
• Security risks: system vulnerabilities caused by integrating components in untested combinations.
• System evolution risks: updated components may be incompatible with user requirements or contain additional undocumented features.

Component Refactoring

• Refactoring components to improve quality is a good practice, but it can be challenging to convince management to expend resources on it.
• Changing software without documenting changes can lead to increasing technical debt.

Learn about designing and constructing traditional components for WebApp functional components following the principles of software architecture. Understand the differences between traditional components and object-oriented components.