Gabriella Balestra

http://socrate.polito.it/biolab

CONSTRUCTION PROCESS AND

DATABASES

INFORMATICA MEDICA

200. INTRODUCTION

01. Strumenti per l’analisi dei fabbisogni e la definizione delle specifiche: definizione di processo, strumenti per l’analisi e la descrizione dei processi

02. Strumenti per l’analisi delle specifiche e la progettazione di software: UML (Use Case Diagram, Use Case Details, Oggetti, Activity Diagrams), Sistemi di codifica

03. Strumenti per la documentazione dello sviluppo di software: UML (…), definizione e principali caratteristiche di una base dati04. Strumenti per la verifica e la validazione di software: differenza tra verifica, validazione e collaudo; UML (piano delle prove e check list)

05. Strumenti per la gestione di dispositivi medici software: normativa e standard, accreditamento e qualità, servizi di ingegneria clinica

06. Principali applicazioni e problematiche aperte

07. Innovazione e futuro dei dispositivi medici software: sistemi di supporto alla decisione clinica, HTA

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Design Implementation

Requirements model

Design model Code

Analysismodel

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The question of how to meet the challenge of organizing software development activities has concerned researchers and practitioners ever since software engineering (SE) emerged as an independent scientific discipline in the 1970s.

The earlier phase is characterized by the mechanistic view of software development (waterfall model).

In the last decade, this view has been replaced by an understanding of development activities as a dynamic process characterized by iterative cycles and the active involvement of all stakeholders (spiral model).

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Requirementsanalysis

Software design

Implementationand integration

Testing

Deployment

Maintenance

The waterfall modelattempts to pin down the requirements early in the project life cycle. After gathering requirements, software design is performed in full. Once the design is complete, the software is implemented. The problem with this method is that if a change in requirements occurs, the impact can be devastating.

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V-modelIn the V Model Software Development Life Cycle, the development & testing activity is started based on same information(requirement specification document).

Based on the requirement document developer team starts working on the design & after completion on design start actual implementation and testing team starts working on test planning, test case writing, test scripting.Both activities are working parallel to each otherTo address this concern , in the V model of testing for every phase , in the Development life cycle there is a corresponding Testing phase.

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UML specification defines two major kinds of UML diagram: structure diagrams and behavior diagrams.

Structure diagrams show the static structure of the system and its parts on different abstraction and implementation levels and how they are related to each other. The elements in a structure diagram represent the meaningful concepts of a system, and may include abstract, real world and implementation concepts.

Behavior diagrams show the dynamic behavior of the objects in a system, which can be described as a series of changes to the system over time.

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Classes describe the different types of objects that are needed within the system. They are the principal elements of an object oriented system.Class diagrams describe the classes and their relationships.

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Class

Attribute

Attribute

Operation

Operation

Attributes and operations are the two elements of a class description:

attributes describe the state of the object andoperations represent the behavior

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ABSTRACTIONThe class definition contains the details of the class that are important for the system. Discarding irrelevant details within a given context is called abstraction.

ENCAPSULATIONIn the object oriented approach an object must contain both data (attributes) and the instructions that affect the data (operations). This characteristics is called encapsulation.Encapsulation is very important because with it a change inside the class does not affect the entire system.

VISIBILITYVisibility is way by means a class can reveal its operations and data to other classes.There are four different types of visibility that can be applied to the elements of a UML model. Public Protected Package Private

(+) (#) (~) (-)

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PUBLIC VISIBILITY

Public visibility is represented by the plus (+) symbol. It allows any other class to directly access the element.Changes in the elements that are public will affect also other classes.

PROTECTED VISIBILITY

Protected visibility is represented by the hash (#) symbol. It allows any operations of the class or belonging to a class that inherits from the class to access the element.

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PACKAGE VISIBILITY

Package visibility is represented by the tilde (~) symbol. It allows any class of the package to directly access the element.

PRIVATE VISIBILITY

Private visibility is represented by the minus (-) symbol. It allows only the operations of the class to access the element.

Classes work together using different types of relationship.

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Classes work together using different types of relationship.

DEPENDENCY

A dependency between two classes means that they work together. It is used when objects of one class works briefly with objects of another class.

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Class A

Class B

ASSOCIATION

Dependency simply allows one class to use objects of another class. Association means that a class will actually contain a reference to one or more objects of the other class in the form of an attribute.

Class A

Class B

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AGGREGATION

Aggregation is a stronger version of association. It is used to indicate that a class owns but may share objects of another class. The empty diamond indicates the owner.

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Class A Class B

COMPOSITION

Stronger aggregation.Class A is made up of Class B and Class C

Class A Class B

Class C

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INHERITANCE OR GENERALIZATIONIt is used to describe a class that is a type of another class.

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A communication diagram, formerly called a collaboration diagram, is an interaction diagram that shows similar information to sequence diagrams but its primary focus in on object relationships.

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On communication diagrams, objects are shown with association connectors between them. Messages are added to the associations and show as short arrows pointing in the direction of the message flow. The sequence of messages is shown through a numbering scheme.

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A sequence diagram is a form of interaction diagram which shows objects as lifelines running down the page and with their interactions over time represented as messages drawn as arrows from the source lifeline to the target lifeline.

OR

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Package diagrams are used to divide the model into logical containers or 'packages' and describe the interactions between them at a high level.

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In UML groups of classes are modeled as packages, but packages can be used to organize any element, for example use cases.