With its focus on the advanced topics of web services, Loosely Coupled covers a lot of ground. The book is organized so that you can read it in sequence, but you may find that you're more interested in certain topics than in others, and therefore prefer to jump around. Either approach will work.

Part I: Perspectives (for all readers)

1. Evolution
2. Web Services
3. The Hype
4. The Missing Pieces
5. Critical Components

If you're new to web services, these chapters will give you the background you need. Even experienced pros will develop an appreciation of the historical and technological perspectives. In Chapters 5, we'll explain why you need to identify your web-services' critical components in order to guarantee success as you develop and deploy them. (Download the latest Web-Services Pyramid from Chapter 5: 700k PDF)

Part II: Concepts (for all readers)

6. A History of Integration
7. Objects and Web Services
8. Service Oriented Architectures
9. Asynchronous Messaging (free download: 459k PDF)
10. Loose Coupling

Next, we'll introduce the concepts that set web services apart from earlier technologies. In Chapter 6, we'll look at the relationships between web services and ERP, EAI, and e-commerce. In Chapter 7, we'll do the same relative to OO technologies. The last three chapters of Part II explore the more advanced topics that are likely new to most IT professionals: SOAs, asynchronous message and queuing, and the all-important but elusive concept of loose coupling.

Part III: Technologies (for developers and managers)

11. Transactions
12. Orchestration
13. Security-The Challenges (free download: 428b PDF)
14. Security-The Solutions
15. Deployment Options

Of all the missing pieces of web services, three are notably unique to web services and SOAs: transactions, security, and the deployment options. For example, even if you're familiar with the principles of ACID-style transactions, you'll discover they're inappropriate for asynchronous web services.

The security issues surrounding web services are so significant, that we've dedicated two chapters to the topic. In Chapter 13, we'll explore the challenges by identifying the missing pieces including the requirements for integrity, authentication, authorization, confidentiality, and non-repudiation. We'll follow that, in Chapter 14, with an introduction to the various platforms for solving those problems, such as SSL, VPNs, XML firewalls, and web-services networks.

Part III ends with a survey of the infrastructure options for web services including web-services networks, gateways, proxies, web-services delivery networks (WSDNs), and web-services providers (WSPs). Chapter 15 also introduces the strategic concept of the solution-evolution timeline, and uses it to show how technologies and standards evolve over time. It's a segue to Part IV.

Part IV: Strategies (for managers and executives)

16. Strategies and Projects
17. Simple Projects (free download: 137k PDF)
18. The Timing of Complex Projects
19. Service Level Agreements
20. Providing External Services
21. A Strategy Checklist (free download: 209k PDF)

In Part IV of Loosely Coupled, we'll show you how to segregate your projects according to those that are simple versus complex, and then we'll present project-management methodologies for each type. In Chapter 18, we'll explore a concept we all know intuitively, but few of us can quantify: that because the costs of developing web services are dropping rapidly, you may be better of delaying the start of your most ambitious web-services projects.

SLAs for web services are in un-charted territory, and in Chapter 19, we'll consider them from both the provider and requestor perspectives. In Chapter 20, we'll look at the issues that are unique to those who are ready to take the plunge and provide web services to business partners. We'll study revenue models, payment methods, contracts, and the robustness requirements for applications and infrastructure. (Are your systems, processes, and staff ready for 24x7 operation and 100% uptime?) Finally, to pull it all together, we've provided a checklist that highlights the significant issues we've presented throughout the book, complete with cross-references to the more detailed discussions.