Architektur & Design. Martin Jud Software-Engineering Construction Architecture 1. Architecture

Transkript

1 Architektur & Design Die Erfahrung hat mich gelehrt, dass man jede Person, die mit gesundem Menschenverstand ausgestattet ist, zu einem guten Systemanalytiker ausbilden kann. Software Architekten und Designer auszubilden ist wesentlich schwieriger. Peter Hruschka. Martin Jud Software-Engineering Construction Architecture 1 Architecture A good Architecture makes it easier to manage change. Architecture is the vehicle for stakeholder communication. Architecture isn t dealing with implementation details. Martin Jud Software-Engineering Construction Architecture 2 Aus der Vorlesung Achritektur von Jörg Hofstetter HTA Luzern

2 Architecture describes the structure or structures of a system, which comprise software components, attributes and responsibilities of these components and the relationships (connectors) among them Martin Jud Software-Engineering Construction Architecture 3 Aus der Vorlesung Achritektur von Jörg Hofstetter HTA Luzern Example: Windows NT Architecture User Mode POSIX Win32 Kernel Mode Windows NT Executive I/O Manager Cache Manager File System Driver Network Drivers Device Drivers Object Manager System Services Process Manager Microkernel... Virtual Memory Manager Hardware Abstraction Layer (HAL) Window Manager Graphic Device Drivers Hardware Martin Jud Software-Engineering Construction Architecture 4 Aus der Vorlesung Achritektur von Jörg Hofstetter HTA Luzern

3 Terms: RUP <-> IEEE RUP IEEE Requirements Requirements (Elicitation + Analysis) Analysis + Design Architecture Detailed Design Design Martin Jud Software-Engineering Construction Architecture 5 Adapted from SWEED Software Process Module, Jörg Hofstetter RUP-Workflow: Analysis & Design #!! "! " Martin Jud Software-Engineering Construction Architecture 6 Adapted from SWEED Software Process Module, Jörg Hofstetter

4 Iterating Requirements and Design SRS C-Requirements D-Requirements What / Was? SDD Architecture Detail-Design (a) (b) How / Wie? Martin Jud Software-Engineering Construction Architecture 7 Aus der Vorlesung Architektur von Jörg Hofstetter HTA Luzern Abstraction Analysis-Model Level of abstraction Design-Model 1 Wohnzimmer, 2 Schlafzimmer 1 Küche, 1 Bad View: Elektroinstallation View: Sanitär Martin Jud Software-Engineering Construction Architecture 8 Aus der Vorlesung Achritektur von Jörg Hofstetter HTA Luzern

5 Aufgaben des Architekturentwurfs Aufgabe analysieren Anforderungen verstehen Vorhandene bzw. beschaffbare Technologien und Mittel analysieren Architektur modellieren und dokumentieren Grundlegende Systemarchitektur festlegen (Architekturmuster und metaphern) Festlegung des Architekturstils Modularisieren Nebenläufige Lösungen in Prozesse gliedern Wiederverwendungs- und Beschaffungsentscheide treffen Ressourcen zuordnen Aspektbezogene Teilkonzepte für Querschnittsaufgaben erstellen Lösungskonzept (als Dokument) erstellen Lösungskonzept prüfen Anforderungen erfüllt? Softwaretechnisch gut? Wirtschaftlich? Martin Jud Software-Engineering Construction Architecture 9 Aus der Vorlesung Software-Engineering von Martin Glinz, Uni Zürich IEEE 1016 Software Design Document SDD 1. Introduction 1.1. Purpose 1.2. Scope 1.3. Definitions, acronyms & abbreviations 2. References 3. Decomposition description 3.1. Module decomposition Module 1 description Module 2 description 3.2 Concurrent process decomposition Process 1 description Process 2 description 3.3 Data decomposition Data entry 1 description Data entry 2 description Architecture 4. Dependency description 4.1 Intermodule dependencies 4.2 Interprocess dependencies 4.3 Data dependencies 5. Interface description 5.1 Module interface Module 1 description Module 2 description 5.2 Process interface Process 1 description Process 2 description 6. Detailed design 6.1 Module detailed design Module 1 detail Module 2 detail 6.2 Data detailed design Data entity 1 detail Data entity 2 detail Martin Jud Software-Engineering Construction Architecture 10

6 Architecture Concerns Techniques: Software structure: layers, client-server... Data-flow, Control-flow Communication Distribution, Parallelity Quality: Security, Stability Error recovery Testability Maintenance, reusability Persistence Martin Jud Software-Engineering Construction Architecture 11 Aus der Vorlesung Achritektur von Jörg Hofstetter HTA Luzern Some Design Goals Extension facilitate adding features Change facilitate changing requirements Simplicity make easy to understand make easy to implement Efficiency attain high speed: execution and/or compilation attain low size: runtime and/or code base Martin Jud Software-Engineering Construction Architecture 12 Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude

7 Architectural Design Patterns Design Goal Provide an interface to a set of objects of various classes. Cause an object to behave in a manner determined by its current state. Encapsulate ways of "visiting" the objects in a collection, so that client code can select a way of visiting at runtime. Facilitate the response of interested entities to changes in a data source. Interpret statements written in a formal grammar. Design pattern Facade State Iterator Observer Interpreter see Martin Jud Software-Engineering Construction Architecture 13 Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude Software Designs Framework classes Class Pattern Models Use casecomponent State Design Design classes Pattern Domain classes Pattern Martin Jud Software-Engineering Construction Architecture 14 Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude

8 Frameworks A Framework is a collection of classes that are usable by several different applications The Java Application Programming Interface (API) is an example of a rich framework which can be used by inheriting from and delegation to framework classes Designing useful and reliable frameworks requires a lot of professional experience in both, software technology and the respective application domain: => do not attempt this without appropriate experience Martin Jud Software-Engineering Construction Architecture 15 One Way to Obtain The Class Model 2. Create and/or use framework classes -- for architecture 3. Create design classes 1. Create domain classes -- specific to this application -- to complete the class model -- from requirements analysis Martin Jud Software-Engineering Construction Architecture 16 Adapted from Software Engineering: An Object-Oriented Perspective by Eric J. Braude

9 Architekturstile Eine Architektur ist im wesentlichen durch die Art der verwendeten Module, die Art(en) der Kooperation zwischen den Modulen die Art der Modularisierung bestimmt. Sind diese drei Arten aufeinander abgestimmt, entsteht ein kohärenter Architekturstil. Martin Jud Software-Engineering Construction Architecture 17 Aus der Vorlesung Software-Engineering von Martin Glinz, Uni Zürich Architecture Viewtypes Module View shows the structure of modules might allow to infer which modules participate in a component Component View shows the structure of the processing units in a running system shows the connections between the processing units does not explicitly show the modules that the component uses Allocation View shows how modules are allocated to development teams or how components are allocated to physical resources. Martin Jud Software-Engineering Construction Architecture 18 Adapted from Systems Design by David L. March, DeSales University Webpage

10 Viewtypes and Styles Martin Jud Software-Engineering Construction Architecture 19 Adapted from Systems Design by David L. March, DeSales University Webpage