se463.txt

# Misc

* How does the practice of Software Engineering differ from Software Development?

Software Engineering is about applying engineering principles to create software.
Software Development is just about creating software.

* What is the difference between a requirement and its corresponding specification?

A requirement is just a condition or capability to be met, but a specification
is a precise and verifiable expression of that requirement.

Requirements come from the environment, but specifications come from the
environment and system combination.

# Requirements

* What is some of the pain caused by bad requirements?

1. Needing to rework code.
2. Having unstable and changing requirements.
3. Having not well-understood requirements, keeping team from focusing on
most important features.

* What is the value of having better requirements?

1. Helps the team focus on the most critical features.
2. Enables better project planning.
3. Enables better testing.
4. Improves team communication.
5. Accelerates software development.

* What is a software requirement?

A capability, property, or constraint that must be met by a solution, for the
solution to be acceptable.

* What are 3 aides for changing requirements?

1. Have a requirements baseline.
2. Understand your business requirements.
3. Keeping the project scope in focus.

* What is the purpose of business requirements?

To identify the primary benefits that a new system is expected to provide.

* What are some examples of business requirements?

Business opportunities, business objectives, success metrics, vision statement.

* How does Agile keep scope creep in check?

Prioritized requirements are kept in the backlog, and only a few requirements
are worked on for a release.

* What is a context diagram?

A graphical representation of:

- The boundary between the Work and external entities.
- Information flows between them

* What are business use cases?

A decomposition of The Work into vertical slices to reduce complexity.

- Represents some end-to-end functionality.
- Triggered by some external event.
- Captures a complete response to a triggering event.
- (Ideally) orthogonal to each other.

* When should you use actor generalization in a use-case diagram?

When actors have a common interesting behaviour, you can factor out the
common behaviour as an abstract actor.

* What is <<include>> used for w.r.t use-case diagrams?

To illustrate a sub use case that is used within multiple other use cases.
To avoid repetition of the same steps in multiple use cases.

* What is <<extend>> used for w.r.t use-case diagrams?

For a sub use case to extend or replace the end of an existing use case.

# Elicitation

* What are some sources of requirements?

Stakeholders, Execution environment, Current situation/problems, Requirements
checklists, Previous systems, Similar systems, Existing documents.

* What is a greenfield system? What is a brownfield system?

Greenfield is a new product, while brownfield is an improvement on an existing
product.

* What is the idea behind artifact-based elicitation?

To learn by studying documentation, systems, artifacts before asking for
stakeholders' time.

* What are some examples of artifact-based elicitation?

- Document studies
- Similar companies
- Norms
- Domain analysis
- Requirements taxonomies

* What is a requirements taxonomy? Give an example.

A classification of requirements.

e.g. PIECES: Performance, Information, Economy, Control, Efficiency, Services

* What is the idea behind stakeholder-based elicitation?

To acquire detailed information about the system-to-be that is problem specific
or stakeholder specific.

* What are some examples of artifact-based elicitation?

- Stakeholder analysis
- Questionnaires
- Interviews
- Observation
- Task Demo
- Ask suppliers
- Domain workshop
- Personas

* What are interviews useful for?

Asking targeted, stakeholder-specific questions.

* Why are group interviews encouraged?

- You get diverse views from different people.
- Responses are richer because of synergy.
- Can reveal conflicts between different groups of stakeholders
- Reduces the spotlight on individuals.

* When are questionnaires useful?

When information has to be gathered from a large number of people, like users.

* What is ethnographic analysis?

Direct first-hand observation of user behaviour, "in the wild".

* When are personas useful?

When real users are not available or are too numerous to interview them all.

* What is the idea behind model-based elicitation?

To re-express the requirements in a different language, which can raise new
questions.

* What are some examples of model-based elicitation?

- Modelling
- Analysis patterns
- Mockups and prototyping
- Pilot experiments

* What are two strategies for creating effective models?

1. Restrict the amount of details we include.
2. Do not restrict the scope of the work being modelled.

* What is the idea behind creativity-based elicitation?

To invent undreamed-of requirements that bring about innovative change and
gives competitive advantage.

* What are some examples of creativity-based eliciation?

- Systemic Thinking
- Brainstorming
- Creativity workshop
- Constraint relaxation

# Conflict

* What is a data conflict?

Multiple conflicting understandings of an issue.

* What is an interest conflict?

Stakeholders have different goals or interests.

* What is a value conflict?

Stakeholders express different preferences.

# Domain model

* What is the mapping criterion w.r.t domain models?

There is an original phenomenon that is mapped to the model.

* What is the reduction criterion w.r.t domain models?

The model reflects only a (relevant) selection of the original's properties.

* What is pragmatic criterion w.r.t domain models?

The model is usable in place of the original, for some purpose.

* What is a domain model?

A model of the operating environment of the Work under study.
A graphical data dictionary of relevant terms and vocabulary used to describe
the Work.

* What are Larman's canonical conceptual classes?

1. Descriptions of tings
2. Catalogs
3. Containers of things
4. Things in a container
5. Other collaborating systems
6. Records of finance, work, contracts
7. Financial instruments
8. Schedules, documents, manuals

* What are the three approaches that Larman recommends for finding domain entities?

1. Refine an existing domain model
2. Use a conceptual class category list
3. Identify noun phrases in use cases and other docs

* What is an attribute w.r.t domain models?

A simple sub-part of an object.

* What is an association w.r.t domain models?

A representation of important relationships between two conceptual classes.

* What is a role w.r.t domain models?

One end of an association.

* When should an association class if used w.r.t domain models?

When a relationship has interesting attributes of its own.

* What is an association qualifier w.r.t domain models?

A special association attribute used at one end of an association to
distinguish among the set of objects at the other end of the association.

* How do you model temporal objects w.r.t domain models?

Create a field that numbers the object (like an id).

* What is a class scope attribute?

An attribute whose value is changeable, but shared by all of the class's object
instances. Denoted by an underline.

# Workflow models

* What is a workflow?

A series of tasks that are organized to accomplish some business use case.

* What is a scenario?

One full execution path through a use case, listing only observable actions.

* What is an alternative path w.r.t scenarios?

A sub use case that achieves the main goal of a use case through a different
intended sequence of actions.

* What is an exception w.r.t scenarios?

A sub use case that captures an unwanted but possible deviation.

* What is an activity diagram?

A UML model for expression the flow of control from one activity to another.

* What is a dataflow diagram?

A functional decomposition of the work, and the data dependencies between
functions.

# Prioritization

* How do most companies prioritize their requirements?

By value (the potential contribution to customer satisfaction) and cost.

* What is the purpose of the Kano model?

It is a method for grouping requirements based on customer perception.
Allows one to select the requirements that deliver the greatest customer
satisfaction.

* What is the 100-Dollar test?

Give stakeholders "100 dollars" to distribute among requirements.

* What is the Analytic Hierarchy Process?

A requirement prioritization technique that does pairwise comparisons of
requirements to produce a relative ranking of requirements.

# Risk Management

* What is risk?

An uncertain factor whose occurrence may result in some loss of satisfaction for
some corresponding objective.

* What is risk exposure?

An expression of the degree of risk.

RE = probability of occurrence * the cost of consequences.

* What is Defect Detection and Prevention?

1. Identify most critical requirements
2. Identify potential risk
3. Estimate the impact of each risk on each requirement
4. Identify possible countermeasures
5. Identify the most effective countermeasures.

# Functional requirements

* What is a user story?

A short simple description of one thing that the user wants to be able to do.

* What are the three C's of user stories?

Card: Stories are written in the syntax "As a <role>, I want <something>, so
that <benefit is achieved>".
Conversation: Discussions with the product owner reveal details of the requiremetns
Confirmations: Acceptance criteria.

* Why are user stories good?

- Easy for stakeholders to understand and remember.
- Shifts the focus from written documentation to discussion
- Encourages iterative development
- Delays elicitation of requirements until just before development
- Supports participatory elicitation

* What is the EARS template?

Easy Approach to Requirements Syntax
A template for structuring the syntax of the one-sentence description of an
atomic requirement.

<optional precondition> <optional trigger> the <system name> shall
<system response>

* What is a ubiquitous EARS requirement?

An invariant behaviour that should always hold.
"The <system name> shall <system response>."

* What is an EARS event-driven requirement?

A requirement that applies when a triggering event is detected at the system
boundary.
"when <trigger> the <system name> shall <system response>."

* What is an EARS state-driven requirement?

A requirement that applies as long as the system is in a particular state.
"while <state> the <system name> shall <system response>."

* What is an EARS option requirement?

A requirement when system behaviour is dependent on the presence of a particular
feature.
"where <feature is included> the <system name> shall <system response>."

* What is an EARS unwanted event?

"if <trigger>", then the <system name> shall <system response>."

# State machines

* What are the three parts of a state machine transition?

1. event(args) - the input event/message that triggers the transition
2. [condition] - a guard condition (no transition if guard is not true)
3. /action - a simple action (e.g. variable assignment)

* How does priority work in a state machine?

The state machine smaller in the hierarchy gets the event.

* What is history w.r.t state machines?

A special state that designates the state that execution was in before it was
last exited.

* What is the difference between history and deep history w.r.t state machines?

Deep history can go down multiple hierarchies. History would just restart the
embedded state machines again.

* What are some good style guides for state machines?

- Use states to model modes of operation.
- Use variables to model other information that affects the flow of control.
- Fewer transitions are better.
- Use concurrency to recognize the orthogonal aspects of the problem.

# Specifications

* What is a specification?

A complete, precise, verifiable expression of requirements of a software or
system solution

* What is domain knowledge w.r.t specifications?

Because we often cannot show that the specifications imply the requirements,
we often need to assume some things about the environment (domain).

* How do you derive specifications?

1. Determine how the system will monitor the environment.
2. Determine whether the requirement constrains environmentally controlled
phenomena.

# Quality requirements

* What is a quality requirement?

A description of extra constraints on what a constitutes an acceptable
solution.

* What are some types of quality requirements?

- Performance
- Reliability
- Robustness
- Adaptability
- Security
- Usability
- Scalability
- Efficiency
- Accuracy/precision

* What is a motherhood requirement?

Expressions such as "reliable" where no one would explicitly ask of their
opposite.

* What is a fit criterion?

A qualification of the extent to which a quality requirement must be met.
e.g. "99% uptime".

* What is the difference between richer fit criteria and the normal kind?

The richer kind divides everything into "outstanding", "target" and "minimum".

* What should you do if you cannot test the fit criteria before delivery?

- Measure the attributes of a prototype.
- Measure secondary indicators
- Estimate a system's quality attributes
- Deliver system and pay penalty if requirements are not met.

* What is a Monte Carlo technique?

Estimating an unknown quantity using a known quantity.

# Prototyping

* What is a prototype?

A partial implementation constructor to enable customers/users/developers to
learn more about a problem or its solution.

* What does User Experience encompass?

All aspects of a user's interaction with the company, its services and its
products.

* What is wireframing?

A visual representation of a user interface, using only simple shapes.

* What is a mockup?

A sketch of the essence of a solution, in terms of screen contents and
navigation among screens.

# Validation

* What is validation?

"Are we building the right product?"

* What is verification?

"Are we building the product right?"

* What are the goals of validation?

Ensure that:
- The specification captures the stakeholders' requirements
- The customer/user is satisfied with the system
- The developers understand the specification.

* What should a validation criteria be?

- Well-formed. (unambiguous, consistent, modifiable, verifiable)
- Valid. (correct and complete)

* How can you perform validation or verification?

- Reviews
- User Feedback
- User Interviews
- Walkthroughs
- Formal Inspections
- Simulation
- Model checking
- Safety Analysis

# Estimation

* What is an estimation?

A prediction of how long a project will take or how much it will cost.

* What is a target w.r.t estimation?

A statement of a desirable business objective.

* What is a commitment w.r.t estimation?

A promise to deliver.

* What can we do to meet our estimates?

Control the project to meet the target.

- Remove noncritical requirements
- Redefine requirements
- Upgrading staff.

* What are some sources of estimation error?

- Uncertainty about numerous details and decisions.
- Omitted activities.
- Optimism
- Bias
- Subjectivity

* What are the biggest influences on estimates?

- Project size
- Kind of software
- Personnel factors

* What is Function Point Analysis?

Generating more precise estimates based on product complexities.

1. Estimate number of function points from the requirements
2. Estimate code size from function points
3. Estimate resources required.

* What is a function point?

The number of "things" needed in the project.

# Stakeholders

* Who is a stakeholder?

Anyone who has a stake in the ultimate success of our project.

* What is the champion stakeholder?

The person paying for the software to be built.

* What is the customer stakeholder?

A person who buys the software after its developed.

* What is the user stakeholder?

Experts on the Work being performed.

* What is a domain expert?

A person that knows the problem domain well.

* What is a software engineer stakeholder?

A technology expert. Estimates cost.