Chapter 7 Advantages and Disadvantages of Web Services

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

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

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

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

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

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

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

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

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

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

Questions and Discussion

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