Module 16:

Physical Design Rationalization

Objectives

At the end of this module, you will be able to Understand project and organizational priorities for

component packaging and distribution Transform objects into services-based components

using the logical design Distribute and package components across the n tiers of the application

Use strategy and prototypes to refine packaging and distribution

Lessons1. Determining a Component

Packaging and Distribution Strategy

2. Transforming Objects into Services-Based Components

3. Distributing Components Across Topologies

4. Refining Packaging and Distribution

Lesson 1: Determining a Component Packaging and Distribution Strategy

Understanding project and organizational priorities for packaging and distribution

Determining Packaging and Distribution

Consider packaging rationales Service category Scalability Performance Manageability Reuse Business context Granularity

Align with programming modelExample: Stateless and scalable

Determine the design trade-offs that impact strategy based on rationales

Reuse and Component GranularityAt what level do you get

maximum reuse and granularity?

Component Granularity

Pote

ntia

l for

Reu

seHigh

LargeSmall

Low

Within each development environment is an optimum component size that maximizes return on reuse

As a class: 15 minutes

ActivityActivity

Activity 11: Considering Design Factors and Trade-offs

Use a hotel property management system as a basis

What types of factors and trade-offs would you consider for a component packaging and distribution strategy?

Lesson 2:

Transforming Objects into Services-Based Components

Transforming objects into services-based components using the logical design

Defining Candidate Components

Remember that the focus of rationalization is distributing services among components

Use candidate components to provide a bridge between logical objects and service distribution

Derive candidate components from the logical object model by iterating through the packaging rationales

Make the first cut at components by using the category-of-service rationale

Business ServicesBusiness Services

User ServicesUser Services

Data ServicesData Services

UserComponent

BusinessComponent

DataComponent

A

BC

D

Preliminary Components

Objects

A

B C

D

Moving from Logical to Physical Design

Lesson 3: Distributing Components Across Topologies

Distributing and packaging components across the n tiers of the application

Defining a Preliminary Distribution

Define components based on category of service and then align them with the proposed component topology

Match services to logical tiers to create a distribution baseline

Validate and use the other rationales in the packaging strategy to evolve the distribution of services

Distributing Candidate Components

User and Business Services

Data andBusiness Services

Business Services

ValidateValidatecustomercustomer

Customer

Updatecustomer

Getcustomer

Replicatecustomer

Customer

ArchiveArchivecustomercustomer

Customer

RetrieveRetrievecustomercustomer

CustomerAssignAssignroomroom

Customer

InvoiceInvoicecustomercustomer

FindFindcustomercustomer

DisplayDisplaycustomercustomer

CustomerCustomer

PreliminaryComponentDistribution

LabLab

Lab 7: Distributing Services to Create Candidate Components

Use your services and objects from Labs 3 and 4

Refer to the Service Distribution Template

Draft a model for distributing the preliminary components across the service tiers

Show work on flip charts

In small groups: 30 minutes

Lesson 4:

Refining Packaging and Distribution

Using strategy and prototypes to refine packaging and distribution

Validating Components

Think of validation as a fundamental aspect of design, not as a distinct design step

Use validation as the trigger for design iteration and evolution

Validate against Packaging strategy Design goals Application requirements Logical design Enterprise architecture

Prototype, prototype, prototype to evolve the deployment model

Possibly update the enterprise architecture

Refining Component Packaging and Distribution

Focus on services instead of components

Use component/service interaction diagrams to document dependencies

Distribute services across component topology as required by packaging rationales

Group services into components based on physical location, packaging rationale, and technology constraints

Use cohesion and coupling to measure the effectiveness of packaging

Address both upward and downward scalability

Cohesion

The relationship among different internal elements of a component

Receive Payment Component

Coupling

The relationship of a component to other components

Enter Gift Shop Charges

Component

Receive Payment Component

Check Out Guest

Component

Packaging Goal

High cohesion

Provides a better definition of the component’s function and behavior

Example: Organizing services by business function so that each component has only the services that pertain to its function

Loose coupling

Provides more flexibility and independence and leads to better defined and simpler interfaces

Example: Organizing relationships among components by business function so that each component interfaces with the minimum number of other components for access to data

In small groups: 15 minutes

ActivityActivity

Activity 12: Repackaging and Redistributing Services

Use the service distribution from Lab 7 as a basis

What is your understanding of techniques for repackaging and redistributing components?

Deliverables of the Rationalization Baseline

Task

Determining a packaging and distribution strategy

Transforming objects into services-based components

Distributing components across topologies

Using strategy and prototypes to refine packaging and distribution

Deliverable

Packaging and distribution strategy

Services-based components

Deployment model Future network topology Future data topology Future component topology

Baselined deployment model

Rationalization Baseline

Rationalization

Summary

What are the packaging rationales?

What is the focus of physical design rationalization?

What is the process for refining component packaging and distribution?

What are cohesion and coupling? What are the packaging goals for cohesion and coupling?

SummarySummary