1. Chapter 7 Advantages and Disadvantages of Web Services

2. Objectives By study of the chapter, you will be able to:
Describe what are the advantages of Web services
Describe what are the completely new business models of Web services
Describe what are the disadvantages of Web services
Analyze the current issues involved in the development of Web services
Questions and Discussion
Homework

3. What are the advantages of Web services?
Interconnectivity and integration with the legacy systems
Modifying internal operations, not outside entities
Knowing the legacy system well before the development and deployment of the Web services
Language free
Interacting with user-friendly GUI
Resulting a state-of-art distributed system that retains all the equity

4. What are the advantages of Web services? (continue)
Lower operational costs
Cheaper than LAN via using the Internet
Low-cost EDI (Electronic Data Interchange)
Remote status reports through the Internet
Remote system management and troubleshooting
Dynamic routing of service people via PDAs
Lower software development cost
Empower of Code-reusable
Reducing of Language barrier
Following W3C (World Wild Web Consortium) rules

5. What are the advantages of Web services? (continue)
Faster system development
Better Web service tools interact with almost any language you are using
Providing rapid development tools by many vendors based on your WSDL (Web Services Description Language)
Providing modern development tools that can also generate Web service code from functional descriptions

6. What are the advantages of Web services? (continue)
Better interfaces with clients
Allowing tighter integration between vendors and their customers
Providing convenience to customers by allowing them to manage their own accounts
Better integration with external business partners
Making easier with your business partners by interactivity and interconnectivity without significant alterations to either one

7. Describe what are the completely new business models of Web services
A virtual enterprise will open new opportunities for all; it makes up of several smaller enterprises. For example:
A hotel in San Francisco booked your room, scheduled your flight, reserved your rental car, and sold you tickets to a NBA game, you would be doing all of these with a virtual enterprise
A new business model of Web services can be described as “Empty-seat selling” in discounting systems, scheduling systems, and online selling systems for the best profitability

8. What are the disadvantages of Web services?
Pitfalls of Web services
Availability: not 100% available at all time
Matching requirements: “one size fits all customers” philosophy is not easy to satisfy all customers’ specialized requirements
Immutable interfaces: Some changed you made may cause customers’ programs to break because you might not know who are using your service

9. What are the disadvantages of Web services? (continue)
Performance issues
Speed: HTTP very transactional in nature will slow down the performance
Overheat: Conversion to and from XML during the communication process will take extra time, especially for binary image data
Adequate choice: Too many to choose in terms of different languages

10. What are the disadvantages of Web services? (continue)
Lack of standards
The current Web services specifications and standards are lacking in the following areas:
Security and privacy: only sending sensitive data to Web services is allowed currently by using HTTPS (Hyper Text transformation Protocol Secure Socket Layer); otherwise, anything sent over the Internet can be viewed by others
Authentication: “Who is contacting me?” is hard to know
Non-repudiation: communication is taking place all time
Billing and contracts: No pricing mechanism or automatic billing system for use of the service yet

11. What are the disadvantages of Web services? (continue)
Provisioning: no agreed upon the standard way to establish user accounts to access Web services
Scalability: no mechanism to expose an existing system such as Java Beans as Web services
Testing: decoupling of the clients from the server makes testing of Web services challenge
Newness of Web service technology
Web services are still in the phase of maturity
Normally a new technology will be under recognized after the four to five year mark
Many vendors who are fighting for market shares may mislead the direction of the development
It’s hard to find qualified and experienced staff to implement a workable solution

12. Questions and Discussion

13. Homework for Extra Points
Answer the following questions:
How can Web services improve customer service?
If Web services have all those problems, should we use them for production-level systems?
Due: Wednesday, May 18, 2005 in the class