Availability Guide for Change Management

Availability Guide for Change Management–125506
v
Contents
New and Changed Information iii
About This Manual xi
Notation Conventions xv
1. Introduction to Change Management
Overview 1-1
What Causes Change? 1-1
Change and the Cost of Downtime 1-1
Increasing Availability by Effectively Managing Change 1-2
What Is Change Management? 1-2
Anticipating and Planning for Change 1-2
Controlling the Introduction of Change 1-3
Installing and Implementing Changes 1-3
Meeting the Goals of Change Management 1-5
Making Changes Online 1-5
Reducing the Time Required for Planned Outages 1-6
Measuring Outages 1-6
Measuring Outages by Outage Minutes 1-7
Measuring User Outage Minutes in a Client/Server Environment 1-7
Alternate Ways of Measuring Outages 1-7
Change Management and the OM Model 1-8
2. Change Control
Overview 2-1
What Is Change Control? 2-1
Implementing Change Control Successfully 2-2
The Change-Control Process 2-2
Phase 1—Definition and Documentation 2-3
Phase 2—Change Planning 2-6
Phase 3—Implementation 2-9
Phase 4—Verification 2-9
Process Flow Diagram 2-10
3. Making System Software and Hardware Changes Online
Overview 3-1
System Software Changes 3-1
Software Configuration Changes 3-1
Installing a New Operating System Release 3-2