3 - Design of Good Information Systems Architectures

Question 1

Process Perspective

Answer 1

Architecture design refers to the process of defining a collection of hardware and
software components and their interfaces to establish the framework for the development of an information
system

Question 2

Outcome Perspective

Answer 2

Architecture design refers to the architecture design process’s outcome, that is the
collection of hardware and software components and their interfaces, which makes up the framework for the
development of an information system

Question 3

Functional Requirement

Answer 3

Functional requirements define the desired features and functions of a system or one of its components. A
functional requirement includes the definition of a functionality and its transformation from an input into a
desired output

Question 4

Nonfunctional Requirements

Answer 4

Nonfunctional requirements are requirements that are not specifically concerned with the system’s
functionality, but rather define general quality attributes and constraints

Question 5

Quality Attributes (8)

Answer 5

• functional suitability
• compatibility
• maintainability
• performance efficiency
• reliability
• security
• portability
• usability

Question 6

functional suitability

Answer 6

functional completeness, functional correctness, and functional appropriateness

Question 7

compatibility

Answer 7

interoperability

Question 8

maintainability

Answer 8

Modularity, modifiability

Question 9

performance efficiency

Answer 9

time behavior (or latency), resource utilization, and capacity

Question 10

reliability

Answer 10

Availability: mean time between failure (MTBF) and the mean time to repair (MTTR)

Question 11

security

Answer 11

Authenticity, accountability, confidentiality, Integrity

Question 12

portability

Answer 12

portability, adaptability, and installability

Question 13

usability

Answer 13

Learnability, Efficiency, Memorability, Errors, Confidence and satisfaction

Question 14

Basic design process activities (6)

Answer 14

1. Making a business case for the system
2. Understanding the architecturally significant requirements
3. Designing or selecting the architecture
4. Documenting & communicating the architecture
5. Evaluating the architecture
6. Ensuring that the implementation conforms to the architecture

Question 15

Activity management Strategies (3)

Answer 15

Waterfall Strategy
Iterative Strategy
Agile Strategy

Question 16

Activity 1: Making a business case (3)

Answer 16

• It documents the expected costs, benefits and risks
• Architects need to be involved in the creation of the business plan
• To help define business cases, various tools have been developed (e.g., SWOT analysis)

Question 17

Activity 2: Understanding the Architecturally Significant Requirements (2)

Answer 17

• An architect needs to filter out the architecturally significant requirements (ASR)
• The quality attribute workshop is a popular approach for both analyzing and eliciting ASRs

Question 18

The requirements analysis

Answer 18

The requirements analysis is the activity of gathering, identifying, and formalizing requirements in order to understand the actual problems for which an architecture, as a solution, is sought, and to learn the purpose and scope of the future system

Question 19

Activity 3: Designing or Selecting the Architecture (4)

Answer 19

• Choose from the most appropriate architecture design options
• Architects need a reliable and rigorous process for selecting candidate architectural solutions to ensure that the decisions mitigate risks and maximize profit
• They can rely on diverse decision making techniques, such as the quality attributes importance description . It describes to what extent a quality attribute is needed
• The result is a specification of architecture components and information about the design rationale

Question 20

Activity 4: Documenting and Communicating the Architecture

Answer 20

• Architecture‘s documentation should be: Informative, Unambiguous, Understandable to many people with varied backgrounds
• Various techniques and tools support the documentation and communication of architectural knowledge, such as Knowledge Architect

Question 21

Architectural Knowledge

Answer 21

Architectural Knowledge is defined as the knowledge about a software architecture and its environment, such as architectural design and architectural decisions, which shape a software architecture and concepts from architectural design (e g components, connectors)

Question 22

Activity 5: Evaluating the Architecture (3 + 4 Methods)

Answer 22

• Determine if the architecture design satisfies the ASRs
• Methods to evaluate the architecture design: Scenario based techniques, Architecture trade off analysis method, Unit testing, Integration evaluation
• If the design turns out to not satisfy the ASRs, a new design must be created

Question 23

Activity 6: Ensuring that the Implementation Conforms to the Architecture

Answer 23

• Architects have to ensure that the actual architecture and its implementation fit together throughout the architecture’s life cycle
• In the maintenance phase, the architecture still can be changed
• When an architectural change causes the interactions to become more complex, which, in turn, obstructs changes to the system, the architecture is degenerating

Question 24

Architectural degeneration

Answer 24

Architectural degeneration is a mismatch between the actual functions of the system and its original design

Question 25

Success of Architecture Design Process

Answer 25

Success remains an ambiguous, inclusive, and multidimensional concept whose definition is bound to a specific context

Question 26

Project success (outdated)

Answer 26

Stay within Iron Triangle dimensions-> Time, Cost, Quality

Question 27

Project success (today)

Answer 27

Measured by considering diverse dimensions in isolation or combination like:

• project safety
• customer satisfaction
• benefits for organizations
• specifications met
• free from defects
• conforms stakeholders expectations
• minimizes disputes and/or conflicts