Designing Software Architectures - Process and Heuristics

Question 1

What are the four levels of abstraction?

Answer 1

1. Constraints and Requierements
2. Architectural Style and technical infrastructure/ logical, rough and distribution architecture level
3. Functional and Technical Architecture Level
4. Program design and implementation

Question 2

In what dimensions does a software architect move during the design process?

Answer 2

• between abstraction levels (y) and software architect activities (x)

Question 3

What is the aim of the task: Analysis of requierements and constraints

Answer 3

• creating central decision criteria, e.g. for decomposition of application into building blocks

Question 4

What is the aim of the task: Designing architecture views and developing technical concepts

Answer 4

• creation of cross-cutting technical themes and tasks
• identification of building blocks based on earlier decision criteria
• development of overall solutions based on different abstraction levels
• selection of best possible solution based on earlier decision criteria

Question 5

What is the aim of the task: Evaluation of architecture and design decisions

Answer 5

• development of different scenarios to make sure, architecture fits goal
• play-out of said scenarios

Question 6

What is the aim of the task: Implementation support and review

Answer 6

• active support for development
• possibly programming

Question 7

What is the benefit of the incremental approach?

Answer 7

• manages uncertainties by revisiting and clearing them
• constant stimulation through communication and common knowledge base
• makes it easier to detect design flaws in an early stage
• contact with different stakeholders

Question 8

What is the first step in the design process?

Answer 8

Gathering of as much information as possible:
- development of domain and technical background knowledge
- determination of existing systems in organisation landscape and investigation to what extent they can be reused
- determination third party applications that solve similar tasks
- reading of technical literature in search of best solution

Question 9

What does the first step of the design process include?

Answer 9

1. development of domain and technical background knowledge necessary for project
2. existing systems determination and analysis to what extent they can be reused
3. third party solutions that solve similiar tasks
4. reading of literature in search of best possible solution for target task

Question 10

What comes after the first step in the design process?

Answer 10

• clarification of the main task of the system to be developed
• based on this, typification of the system into information system, embedded system, mobile system
• based on type of system follow up questions arise

Question 11

What are the influencing factors of the design process?

Answer 11

• product related factors
• political and organizational factors
• operational and technical factors
• trends

Question 12

What do the following influencing factors include?
product-related factors

Answer 12

• functionality factors (what system needs to do)
• quality factors (what criteria needs to be fulfilled for the system to be suitable for use)

Question 13

What do the following influencing factors include?
Operational and technical factors

Answer 13

• what is the existing system landscape
• origin often in infrastructure and existing applications

Information like:
- programming specification
- programming languages
- programming interfaces
- software infrastructures
- Rerefence Architectures
- libraries, frameworks, components
- analysis and design methods

Question 14

What do the following influencing factors include? Organizational and political factors

Answer 14

• organization structure
• resources (team members, budget, …)
• organizational standards (process, acceptence, …)
• legal and regulatory concerns
• change often very costly therefore rare

Question 15

What are Design Heuristics?

Answer 15

• proven fundamental principles how to solve problems efficiently
• difference to reference architectures, not concrete details on implementation

Question 16

Name relevant Design Heuristics

Answer 16

• Top-Down / Bottom-Up approach
• Hierarchical (de-)composition
• conceptual integrity
• Expect errors
• Postels law

Question 17

What are important principles of Decomposition?

Answer 17

1. encapsulation / black box
2. iterative approach
3. check reusable other parts
4. independent and seperation of concerns

Question 18

What is part of Hierarchical (de)composition?

Answer 18

• Decomposition principles
• KISS
• Seperation of concerns