System Engineering Midterm Notes Flashcards
(37 cards)
What is the objective of Requirements Engineering (RE)
Utilize RE personnel, processes, tools and support facilities:
- To lower system costs
- To minimize technical risk
- To reduce development time
- and to improve the quality of new systems and applications
Overall, make a good product and a nice & smooth development project possible
Why RE?
Customer: Knows what he needs
RE engineer: Specifies it precisely
Developer: Understands the product development precisely
Who are the stakeholders for requirements? What is their connection to the Requirements Engineering Department?
- Customer
- Quality Management
- Testers
- Developers
- Manufacturing
- Management
- Program Management
- Standardization Institutes
The stakeholders voice out needs & requirements to the RE team.
How does the RE team make structured and meaningful requirements?
- Methods
- Tools
What are some examples of Structured and Meaningful Requirements?
- System Requirements
- Software Requirements
- Hardware Requirements
- Mechanical Requirements
- comments, proposals, hints
etc.
The Requirements Engineering team consists of two parts, what are they?
Requirements Management & Requirements Development
What is Requirements Management?
Focus: Receive and Organize Requirements
- Plan & Control RE Activities
- Establish a Structure
- Trace Requirements
- Prioritize and Plan For Realization
- Manage Requirements Change
What is Requirements Development
Focus: Creation of Requirements
- Detect Requirements
- Analyze Requirements
- Document Requirements
- Verify & Validate Requirements
- Analyze Impact of Changes
What is a Requirement?
- A condition or capability needed by a user to solve a problem or
achieve an objective - A condition or capability that must be met or possessed by a
system or system component to satisfy a contract, standard,
specification or other formally imposed documents. - A documented representation of a condition or capability as in 1
or 2
Requirements should specify WHAT and not HOW.
i.e. understand and specify the PROBLEM to be solved rather than the SOLUTION.
What can requirements be associated with?
- Stakeholder
- Vehicle
- System
- System Component
- Disciplines (SE/EE/SW/ME)
What are detailed requirements dependent on?
Architectural design
What are the two phases of a RE Cycle??
A - Identify Requirements
B - Analyze Requirements
A - Identify Requirements
1. Requirements Collection and Coarse Structuring
2. Requirements Detailing
B - Analyze Requirements
3. Analysis and first Design Consideration
4. Review and Approval
What happens in Requirements Collection and Coarse Structuring?
- Collect Requirements from various sources (Low details with
headlines or very simple desc) - Develop a structure with reasonable coherent chapters
- Generate first version of product maturity plan
Steps in, 1. Identifying collection of requirements
Identify Stakeholders:
- Who has an interest in our product?
- Who will use the functionality?
- Who in the organization will use the system?
- Who will take part in development of the product?
- What are external resources of the system
- What other systems will need to interact with this one?
- Interviews and Workshops with Stakeholders and Experts
- Document Analyses
Possible external Sources
− Customer Requirements Specification
− Any information received from the customer (e.g.
mail, dialogue, meetings)
− Competitors’ systems
− Standards and Norms (e.g. IEC 61508 Functional
safety of electrical/electronic/programmable electronic
safety-related systems)
− Technical research studies
− Laws (regulation need)
− Patents and patent situation
− etc.
Possible internal sources
− Long-term product strategy of the company
− Market surveys
− Quality goals (safety, reliability, performance,
usability)
− Internal re-use strategy
− Requirements of preceding projects
− Module and / or Integration tests
− Manufacturing
− Validation
− Lessons learned database
− Feedback from Architecture or Design Phase
− etc.
- Requirements Detailing?
- Refine Requirements in collaboration with domain experts
- Achieve Completeness
- Achieve precision
- Analysis and first Design Consideration?
- Check for consistency
- Check for design implications and feasibility
- Involve Project partners
- Prioritize “High risk first” and synchronize with product maturity
plan
- Review & Approval
- Conduct Review to identify
remaining issues - Involve stakeholders
Good Requirements
- Express what our customer wants
to obtain / what has been agreed
to deliver to him - are specified in a way that
different backgrounds will come to
the same understanding of these
requirements - are processed in a way that they
can be used later on in this project
and as well as for other projects
too
How to write good requirements?
- Needed
- Atomic
- Verifiable
- Design-independent
Summary of a good requirement
Completeness of Information
- one requirement per
Requirements-Object
- Always use active tense
- Replace references with the
referenced terms
- Always use the same word for the
same item
Conciseness
- Eliminate flowery phrases
- Use lists/enumeration to structure
complex requirements.
- Use diagrams/sketches to
illustrate complex requirements
Wording
- Express mandatory requirements
with “shall”/”shall not”
- Express descriptions/statement
with “to be”
Documentation Strategy
- Single source principle:
1. no information duplication
2. no redundant information - “off the shelf” principle:
1. standardized for all projects
2. easy navigation - documentation of functions top down
- integration of all documents of the project team into one information data base
- unambiguous simple structure
What is System Integration?
Integration is the reverse activity of decomposition: the different broken-down parts of a physical component are assembled (integrated) together in an appropriate order.
An Integration Plan consists of two parts:
- The integration strategy and 2. the integration steps define the order in which the broken-down parts are integrated
What are some System Integration Strategies?
- Global Integration
- Integration “with the stream”
- Incremental Integration
- Subsets Integration