1. Prepared by Celeste Ng SaaS, Utility Computing, Grid Computing, Pervasive Computing Summarized from:Turban, Efraim, Leidner, Dorothy, Mclean, Ephraim, Wetherbe, James, Information Technology For Management - Transforming Organizations in the Digital Economy, John Wiley & Sons, 6th Edition, 2009.

2. Prepared by Celeste Ng The SOFTWARE-AS-A-SERVICE BUSINESS MODEL Computing resources are made available to user when the resources are needed is the Software-as-a- Service(SaaS) model. Paid for through a fixed subscription fee, or payable per an actual usage fee. To overcome the common challenge to an enterprise of being able to meet fluctuating demands efficiently. E.g. utilitycomputing.itworld.com, utilitycomputing.com, oracle.com/ondemand, Salesforce.com (on demand service for customer relationship management(CRM))

3. Prepared by Celeste Ng SaaS: The Utility Computing Concept Utility computing is computing that is as available, reliable, and secure as electricity, water services,and telephony. Have computing resources available on demand from virtual utilities around the globe.

4. Prepared by Celeste Ng Limitations of Utility Computing Key pieces of the technology are still missing. Is hard to do in heterogeneous data centers. Works better for some applications than for others. Needs extra security. Based on a survey, other concerns include: Vendor dependency and lock in(50.8%), Performance and reliability(45.9%), Business data too critical to trust to outsiders(41.6%), Loss of control over key resources(38.3%)

5. Prepared by Celeste Ng GRID Computing Coordinates the use of a large number of servers and storage,acting as one computer. Many of the current grid applications are in areas that formerly would have required supercomputers. A well-known grid-computing project is the SETI Home project. PC users worldwide donate unused processor cycle times to help the search for signs of extraterrestrial life by analyzing signals coming from outer space. Project to harness the unused processing power of the user’s computers. Save the project both money and resources.

6. Grid Computing Applications „ The Cancer Institute of New Jersey ‰ With IBM researchers, they use Grid computing to convert hundreds of thousands of images of cancerous tissues and cells, from cancer centers around the country, into digital images „ Financial services firm Wachovia Corp. ‰Use grid computing to draw computing power from servers spread across cities in US and London „ Paypal ‰ Use grid computing in its electronic payment processing system Prepared by Celeste Ng

7. Pervasive computing A future in which computation becomes part of the environment. Computation will be embedded in things, not in computers.