Agenda

• Modeling and Simulation Model
• SW Requirements - Metamodel
• Finding Requirements
• Requirements Workflow Detail
• Use Case Workflow Detail
• Use Case Modeling
• Detail a Use Case

Modeling and Simulation Model

• A referent in software is usually defined by a SW requirements model.

Ways of using UML

1. UML use case diagrams and use case realizations as sketch - result of use case analysis
2. UML use case diagrams and use case realizations as blueprint - result of a use case design process based on use case analysis
3. UML as programming language - UML diagrams are compiled directly to executable code

SW Requirements - Metamodel

• Requirements tell us what we should build, not how we should build.
• Use "shall" statements to capture requirements.
• Functional requirements - what the system should do, e.g.,
  • Customers
  • Products
  • Orders
  • Sales channels
  • Payments
• Non-functional requirement - a constraint on the system, e.g.,
  • Performance (wydajność)
  • Capacity (przepustowość)
  • Availability (dostępność)
  • Compliance to standards

In the requirements metamodel

• UML packages are grouping mechanisms
• small triangle indicates that the package contains a model
• the anchor icon indicates that the thing at the circle end contains the thing at the other end of the line
• The term actor is used to describe the role played by people or things that use the system. 
  • A role is like a hat that something wears in a particular context.
• A use case describes behavior that the system exhibits to benefit one or more actors.

Finding Requirements

Requirements come from the context of the system you are trying to model. This context include:

• direct users of the system
• other stakeholders (inni udziałowiecy) (e.g., mangers, maintainers, installers)
• other systems with which the system interacts
• hardware devices with which the system interacts
• legal and regulatory constraints
• technical constraints
• business goals

Stakeholders involved in system acquisition - modeling needs to improve communication

Unified Process (UO) Workflow Detail

A workflow detail shows us the workers and activities involved in a particular workflow. A workflow detail specifies (details) the component tasks and related roles of a specific workflow.

• UP workflows details are modeled as workers (roles) and activities.
• Note that that this is only a approximation of the workflow in the "average" case and might not be a particular exact representation of what happens in practice.
• In the real world, you can expect some tasks to be done in a different order or in parallel according to circumstances.

Requirements Workflow Detail

A requirement model  workflow detail defining functional and non-functional requirements.

Use Case Requirements Workflow Detail

A use case requirement workflow detail defining UML use cases.

Use Case Modeling

Use case modeling typically proceeds as follow:

• Find a candidate system boundary - a box drawn around the use cases to denote the edge of boundary of the system being modeled..
• Find actors.
  • To find actors ask: Who or  what uses or interacts with the system?
• Find use cases:
  • specify the use case
  • identify key alternative flows
• Iterate until use cases, actors, and system boundary are stable with meaningful relationships between actors and use cases.

Feature list is a set of candidate requirements that might take the form of a vision document or similar.

Capture business language and jargon in the project glossary.

Detail a Use Case