module 16: physical design rationalization. objectives at the end of this module, you will be able...
TRANSCRIPT
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