Vorlesung 4

Question 1

Tasks of the architect (3 nennen)

Answer 1

Identify and know the stakeholders

Involve the stakeholders early and continuously

Know their concerns (real needs & wishes)

Manage their expectations (Prioritize, not every wish can be fulfilled. Make tradeoffs.)

Question 2

What drives my architecture?

Answer 2

Whatever is…

… costly to change

… risky

… new

Question 3

What are architectural drivers?

Answer 3

business goals (customer organization, developing organization)

quality attributes (system in use, system under development)

key functional requirements (unique properties, make system viable)

constraints (organizational & legal & technical, cost and time)

Question 4

notations (Bezeichnung) for architecture drivers

Answer 4

business goals (natural language, links to other documents)

constraints (natural language)

quality attribute (drivers, scenarios)

key functional requirements (use cases, user stories)

Question 5

Why invest into architecture drivers?

Answer 5

requirements are often …

not well analyzed and documented

not complete

do not cover development and operation aspects

& somtimes amount of requirements is so big that architects have to condense

Question 6

What are problems with quality attributes and how can they be tackled?

Answer 6

There is no standard set of quality attributes

Difficulty of measuring the achievement of the quality attributes

———–> architecture drivers help us to avoid these problems

Question 7

Purpose of architectural drivers

Answer 7

compensation (of missing/unknown requirements, of complex exceptional cases)

aggregation (of large amouints of similar or repeating requiremtns)

consolidation (of different stakeholder opinions and concerns, of invesments into future)

negotiation (between external quality (runtime) and internal quality (devtime), to align conflicting stakeholder concerns, to meet constraints)

Question 8

What are some exemplary quality attributes for distributed systems? 3 nennen

Answer 8

 Availability: ability to continue operation after a computer/piece of equipment failed
 Reliability: continuity of correct service
 Performance: timely response to service request events, throughput, jitter
 Scalability: continue to function as expected when it (or its context) is changed in size or volume
 Security: ability to resist unauthorized attempts to access data and services
 Safety: ability to mitigate consequences of critical failures
 Integrity: absence of improper system alterations
 Openness: use of equipment and software from different vendors
 Maintainability: ability to undergo modifications and repairs
 Testability: verification of the correctness of the system
 Portability: ability to port system to other platforms / technologies

Question 9

Flow chart from drivers to solution

Answer 9

concern elicitation

design exploration

reasoning

decision making

Question 10

architecture definition workflow

Answer 10

architecture drivers (input) 1:1 driver solutions (output)

driver solutions (output) n:m decision rationales (output)

decision rationales (output) n:m architecture diagrams (output)

Question 11

architecture decision making

Answer 11

ppt

Question 12

what decisions or steps are part of perspectives/solutions concept

Answer 12

PPT