Important Questions and Answers: UML state diagrams and modeling

UML state diagrams and modeling

PART- A

1. Define post condition.

The post conditions describe changes in the state of objects in the Domain Model. Domain Model state changes include instances created, associations formed or broken, and attributes changed.

2. Define Attributes.

 An attribute is a logical data value of an object.

3. When Are Contracts Useful?

The use cases are the main repository of requirements for the project. They may provide most or all of the detail necessary to know what to do in the design, in which case, contracts are not helpful. However, there are situations where the details and complexity of required state changes are awkward to capture in use cases.

4. Mention the Guidelines for Contracts.

To make contracts:

1.       Identify system operations from the SSDs.

2.       For system operations that are complex and perhaps subtle in their results, or which are not clear in the use case, construct a contract.

3.       To describe the post conditions, use the following categories:

-        Instance creation and deletion

-        attribute modification

-        Associations formed and broken

5. What are Steps for Mapping Designs to Code?

Implementation in an object-oriented programming language requires writing source code for:

-        Class and interface definitions

-        Method definitions

6. Creating Class Definitions from DCDs.

At the very least, DCDs depict the class or interface name, super classes, method signatures, and simple attributes of a class. This is sufficient to create a basic class definition in an object oriented programming language. Later discussion will explore the addition of interface and namespace (or package) information, among other details.

7. What are the Benefits of Iterative Development?

-Early rather than late mitigation of high risks (technical, requirements, objectives, usability, and so forth)

-        Early visible progress

-        Early feedback, user engagement, and adaptation, leading to a refined system that more closely meets the real needs of the stakeholders

-        managed complexity; the team is not overwhelmed by "analysis paralysis" or very long and complex steps

-The learning within iteration can be methodically used to improve the development process itself, iteration by iteration

8. Define Events, States, and Transitions.

An event is a significant or noteworthy occurrence.

For example:

A telephone receiver is taken off the hook.

A state is the condition of an object at a moment in time—the time between events.

For example:

-A telephone is in the state of being "idle" after the receiver is placed on the hook and until it

Is taken off the hook.

A transition is a relationship between two states that indicates that when an event occurs, the

Object moves from the prior state to the subsequent state.

For example:

- When the event "off hook" occurs, transition the telephone from the "idle" to "active" state.

9. What is meant by State chart Diagrams?

A UML state chart diagram, as shown in Figure 29.1, illustrates the interesting events and states of an object, and the behavior of an object in reaction to an event. Transitions are shown as arrows, labeled with their event. States are shown in rounded rectangles. It is common to include an initial pseudo-state, which automatically transitions to another state when the instance is created.

10. State chart Diagrams in the UP?

There is not one model in the UP called the "state model." Rather, any element in any model (Design Model, Domain Model, and so forth) may have a state chart to better understand or communicate its dynamic behavior in response to events. For example, a state chart associated with the Sale design class of the Design Model is itself part of the Design Model.

11. Utility of Use Case State chart Diagrams.

-        Hard-coded conditional tests for out-of-order events

-        Use of the State pattern (discussed in a subsequent chapter)

-        disabling widgets in active windows to disallow illegal events (a desirable approach)

-        A state machine interpreter that runs a state table representing a use case

State chart diagram.

12. List out the types of Events.

-External event

-Internal event

-Temporal event

13. Define External event.

External event—also known as a system event, is caused by something (for example, an actor) outside our system boundary. SSDs illustrate external events. Noteworthy external events precipitate the invocation of system operations to respond to them.

- When a cashier presses the "enter item" button on a POS terminal, an external event has occurred.

14. Define internal event.

Internal event—caused by something inside our system boundary. In terms of software, an internal event arises when a method is invoked via a message or signal that was sent from another internal object. Messages in interaction diagrams suggest internal events. - When a Sale receives a make Line item message, an internal event has occurred.

15. Define temporal event.

Temporal event—caused by the occurrence of a specific date and time or passage of time. In terms of software, a temporal event is driven by a real time or simulated-time clock.

-Suppose that after an end Sale operation occurs, a make Payment operation must occur within five minutes, otherwise the current sale is automatically purged.

PART- B

1. Explain UML State Machine Diagrams and Modeling.

 -Definition

-How to apply

-Example

-Process

2. What is the operation of contracts works.

-Contracts -Contract Sections -Post conditions

-Guidelines: Contracts

-Next Gen POS Example

-Changes to the Domain Model -Contracts, Operations, and the UML -Operation Contracts With in the UP

3. Explain the operation of Mapping Designs to Code.

- Programming and the Development Process -Mapping Designs to Code

-Creating Class Definitions from DCDs -Creating Methods from Interaction Diagrams -Container/Collection Classes in Code -Exceptions and Error Handling

-Defining the Sale—make Line Item Method

-Order of Implementation

-Test-First Programming

4. What is operation of UML Deployment and Component Diagram? Draw the diagram for a banking application.

-Deployment Diagram

-Component Diagram

PART C

State diagrams

State diagrams are used to describe the behavior of a system.

Activity diagrams

Activity diagrams describe the workflow behavior of a system.

Deployment diagrams

Deployment diagrams show the physical relationship between hardware and software in a system.

Component diagrams

Component diagrams show the software components of a system and how they are related to each other.

Structural modeling

Structural modeling captures the static features of a system.

Behavioral model

Behavioral model describes the interaction in the system.

Architectural model

Architectural model represents the overall framework of the system.