Ch 04

Question 1

EO 4.1.1

key reasons for requirements documentation

Answer 1

Documentation plays a goal-orientated supporting function in communication. The following factors make this support necessary. Requirements are long-lasting, legally relevant and should be accessible to all. Requirements documents are complex.

Question 2

EO 4.2.1

The three perspectives of functional requirements

Answer 2

Data perspective

Behavioral perspective

Functional perspective

Question 3

EO 4.2.2: 1/2

Knowing advantages of natural language requirements documentation

Answer 3

Advantages of natural language

1. No stakeholder has to learn a new notation.
2. The language can be used for miscellaneous purposes 3. The requirements engineer can use natural language to express any kind of requirement.

Question 4

EO 4.2.2: 2/2

Knowing disadvantages of natural language requirements documentation

Answer 4

Disadvantages of natural language

1. natural language can allow requirements to be ambiguous
2. requirements of different types and perspectives are in danger of being unintentionally mixed up during documentation.
3. In that case, it is difficult to isolate information pertaining to a certain perspective amidst all of the requirements in natural language.

Question 5

EO 4.2.3:
the most important model-based requirements documentation form
1. System function 
2. Structural data modeling  
3. Sequence modeling 
4. Event driven behavior

Answer 5

1. System function: use case diagram
2. Structural data modeling: Class diagram
3. Sequence modeling: Activity diagram
4. Event driven behavior: State diagram

Question 6

EO 4.2.4:

the advantages of mixed form of requirements documentation

Answer 6

“The combination allows the disadvantages of both documentation types to be decreased by means of the strengths of the other documentation type, and combining documentation types exploits the advantages of both. For instance, models can be amended or complemented by natural language comments and natural language requirements and natural language glossaries can be summarized and their dependencies can be depicted clearly by making use of models.”

Question 7

EO 4.3.1

the advantages of standardized document structures

Answer 7

1. Standard outlines simplify incorporating new staff members.
2. Standard outlines allow for quickly finding desired contents.
3. Standard outlines allow for selective reading and validation of requirements documents.
4. Standard outlines allow for automatic verification of requirements documents (e.g., with regard to completeness).
5. Standard outlines allow for simplified reuse of the contents of requirements documents.

Question 8

EO 4.3.2

The 3 widespread document structures

Answer 8

1. Rational united process (RUP)
2. IEEE standrad
3. V model

Question 9

EO 4.3.3

important points for a tailored standard structure

Answer 9

1. Introduction:
2. propose 2. System coverage 3. Stakeholders 4. Definitions, abbreviations 5. references 6. overview
3. General overview:
4. System environment 2. architecture description 3. System functionality 4. users and target audience 5. constrains 6. Assumptions
5. Requirements
6. Appendices
7. Index

Question 10

EO 4.5:

quality criteria for requirements documents

Answer 10

1. Unambiguity and Consistency Requirements documents can be consistent and unambiguous only when the individual requirements are consistent and unambiguous. In addition, it must be guaranteed that individual requirements do not contradict one another.
2. Clear Structure In order to guarantee that the requirements document is readable by any stakeholder, it should be appropriately comprehensive and clearly structured.
3. Modifiability and Extendibility Requirements documents must be easy to extend. There are always requirements that are changed, altered, added, or removed as a project progresses.
4. Completeness Requirements documents must be complete, i.e., they must contain all relevant requirements (and required additional information), and each requirement must be documented completely.
5. Traceability An important quality criterion is traceability of relationships between requirements documents and other documents (e.g., business process model, test plans, or design plans).

Question 11

EO 4.4.1

uses requirements documents

Answer 11

Planning

Architectural design

Implementation

Test

Change management

System usage and system maintenance

Contract management

Question 12

EO 4.6.1

quality criteria for requirements (single requirement)

Answer 12

agreed

unambiguous

necessary

consistent

verifiable

feasible

traceable

complete

understandable

Question 13

EO 4.7.1

contents and importance of glossary

Answer 13

A frequent cause of conflicts, arising in RE, lies in the different understanding of terminology among the involved people. To prevent this problem, it is necessary that all relevant terms are defined in a glossary. A glossary is a collection of term definitions for:

• context-specific technical terms
• abbreviations and acronyms
• everyday concepts that have a special meaning in the given context
• synonyms
• homonyms

Question 14

EO 4.7.2

the rules fire handing the glossary

Answer 14

The glossary must be managed centrally

The responsibilities for maintaining the glossary must be defined

The glossary must be maintained over the course of the project

The glossary must be commonly accessible

Use of the glossary must be obligatory

The glossary should contain the sources of the terms

The stakeholders should agree upon the glossary

The entries in the glossary should have a consistent structure