1. CSCI 578 Software Architectures
Exam #1 Review

2. Materials you are responsible for
Chapters 1-7 in the text book
All lecture material through intro to Architectural Analysis (Week 8)
Homework #1 and #2

3. Exam Closed book, closed note Format Write in answers
No multiple choice

4. Material Review Canonical elements of software architecture Component
computation
Connector
communication/coordination
Configuration
topology and constraints

5. Material Review Architectural styles Architectural patterns
Codify key constraints and architectural elements (components, connectors, configurations) found effective used in a family of software systems over a given time period
Architectural patterns
A set of architectural design decisions that are applicable to a recurring design problem, and parameterized to account for different software development contexts in which that problem appears.
Compared to styles, architectural patterns are at a coarser level of granularity (design decisions versus actual architectural elements) and are inherently more domain specific

6. Material Review Examples of Architectural Styles
Client/Server, P2P, Object Oriented, Layered, Data-Flow, Pipe and Filter, Blackboard, Rule Based
Examples of Architectural Patterns
3-tier (Stage-Logic-Display), MVC, Sense Compute Control
Methods of evaluating design methods like styles and patterns
Vocabulary, structural patterns, computational model, invariants, common examples, disadvantages, specializations
Methods of design
Greenfield design (entirely fresh start, no baggage)
Analogy searching, Brainstorming, Literature searching, Morphological Charts, Removing Mental Blocks, Insight from requirements/implementation

7. Material Review Software Connectors Benefits of first-class connectors
Taxonomy
4 main roles
Communication, Conversion, Facilitation, Coordination
8 main types
Event, Stream, Procedure Call, Arbitrator, Data Access, Distributor, Linkage, Adaptor
Benefits of first-class connectors
Software evolution, separation of concerns, modularity, pluggability

8. Material Review Architectural Modeling How to choose what to model?
An architectural model is an artifact that captures some or all of the design decisions that comprise a system’s architecture
Architectural modeling is the reification and documentation of those design decisions
How to choose what to model?
Cost/Benefit Decision
What do we model?
Structure (Architectural element), static/dynamic behaviors, functional/non-functional aspects, Views/Viewpoints

9. Material Review Architectural Modeling Important things to “get right”
Consistency, Accuracy/Precision, Ambiguity
How do we evaluate modeling techniques?
Scope/Purpose, Basic Elements, Style, Static/Dynamic Aspects, Dynamic Modeling, Non-functional aspects, ambiguity, accuracy/precision, viewpoints, view consistency
Modeling approaches
Generic, early ADLs, style-specific and domain-specific languages, extensible ADLs

10. Material Review Architectural Modeling Generic approaches Early ADLs
Natural language, informal graphical tools (Powerpoint), semi-formal graphical tools with semantics (UML)
Early ADLs
Darwin, Rapide, Wright
Domain/Style-specific ADLs
Koala, Weaves, AADL
Extensible Architecture Description Languages
xADL, ACME, ADML

11. Material Review Architectural Visualization
An architectural visualization defines how architectural models are depicted, and how stakeholders interact with those depictions
Two key aspects here:
Depiction is a picture or other visual representation of design decisions
Interaction mechanisms allow stakeholders to interact with design decisions in terms of the depiction

12. Material Review Viz Model Viz Model Viz Model Viz Viz Model Model
One (canonical) visualization (common)
Viz
Model
Viz
Model
Viz
Viz
Model
Model
Many visualizations for one model (common)
One visualization bringing together many models (uncommon)

13. Material Review Kinds of Architectural Visualizations
Textual (XML in a text editor, natural language, etc.)
Graphical (boxes, lines, etc.)
Hybrid (combine elements of textual and graphical)
Effect (depict the results or effects of design decisions, not direct design decisions)
How do we evaluate architectural visualizations?
Scope/Purpose, Basic Type, depiction, interaction, fidelity, consistency, comprehensibility, dynamism, view coordination, aesthetics, extensibility

14. Material Review Architectural Analysis
The activity of discovering important system properties using the system’s architectural models.
Early, useful answers about relevant architectural aspects
Available prior to system’s construction
Formal/Informal
Largely dependent on the underlying architectural model’s expressivity
Concerns
Goals, Scope, Primary architectural concern, level of formality, Type, Level of automation, System stakeholders

15. Material Review Architectural analysis Completeness Consistency
Does the architectural analysis take all the system elements (components/connectors/etc.) into account? Does it take the other aspects (requirements, etc.) into account?
Consistency
Do the results of analysis on one subset of a software system produce non contradictory results with respect to the analysis of another (perhaps non-disjoint) subset?
Name, Interface, Behavior, Interaction, Refinement
Compatibility
Do the results of analysis conform to the expected properties/results of the specific domain, style, or reference architecture?
Correctness
Does the architectural analysis really represent properties of the full system specification? Does the system implementation represent the predicted analysis?

16. Material Review Architectural analysis Scope Techniques for analysis
Component/Connector
System/Subsystem
Data
Refinement/Abstraction levels
Comparing architectures/analysis
Techniques for analysis
Inspection-based, Model-based, Simulation-based