1. MP3 / MD740 Strategy & Information Systems Sept. 29, 2004 The Evolution of Software Technologies, Computing Architectures, and their Business Implications: Software as a Service, Java, Distributed Computing, and Web Services

2. Topics Covered ASPs / HSVs –Software as a service Computing Platforms and Java –Understanding the relationship between technology, strategy, and product adoption Architectures –enable the range of technical options (and hence business options) available to a firm –implications regarding cost, flexibility, security Host / Terminal Model –Old school, still enforced Client / Server Model –Request / Response Web Services –Linking applications made easier

4. Traditional Programs... RealPlayer for Windows RealPlayer for Macintosh Windows Compiler Macintosh Compiler Intel code 10010 01001... 01011 00101... PowerPC code … are written for an Operating System (Windows, Macintosh, etc.) & compiled for a microprocessor (Intel x86, Power, Sun UltraSPARC, Compaq Alpha, etc.). Compiled code is ready to be executed by the appropriate microprocessor (fast). DrawWindow()… … GetWindow()… …

5. "[The Windows API] is so deeply embedded in the source code of many Windows apps that there is a huge switching cost to using a different operating system instead. It is this switching cost that has given the customers the patience to stick with Windows through all our mistakes, our buggy drivers, our high TCO [total cost of ownership], our lack of a sexy vision at times, and many other difficulties. Customers constantly evaluate other desktop platforms, [but] it would be so much work to move over that they hope we just improve Windows rather than force them to move." -- Microsoft C++ general manager Aaron Contorer explains Windows' greatest selling point in a 1997 memo to Bill Gates. [source: San Jose Mercury News GMSV]

6. Java - a Cross-Platform Standard Java Consist of Two Components –object oriented programming language –virtual machine (software that executes Java byte code) Advantages –write-once run-anywhere. Runs on any machine with a JVM (Java Virtual Machine) regardless of OS or microprocessor –object-oriented language (reuse, faster dev.) –secure Disadvantages –slow due to download times –slow due to interpreting line by line –inconsistent Java Virtual Machines

7. Java Programs... Java ProgramJava Compiler Windows, Intel JVM 00010 11110... … are written for the Java Virtual Machine (JVM). In theory, the same Java byte code can execute on any computer with a standard JVM, regardless of OS or processor (write once, run anywhere). Byte code is interpreted line-by-line for each processor (slow). OpenWindow()… … Macintosh, PowerPC JVM Sun Solaris, Sparc JVM Compaq UNIX, Alpha JVM Java byte code 10110 00110... 01011 01100... 11000 01010... 01111 01100... …and more (code is generic & must be interpreted) (JVM software is the interpreter)

8. Java is Often Confused With... JavaScript –interpreted programming language that co-exists in same files as HTML (doesn’t need to be compiled into byte code) –slower than Java –easier to program (you see this in your class assignment) –supported by Netscape & Microsoft (w/some consistency problems) –unlike Java, can only be used to create web pages (Java can be used to create stand-alone applications that execute outside the browser).

9. Java is Often Confused With... In-Browser applications (ActiveX, Plugins) –ActiveX is Microsoft's component technology architecture (e.g. a way to string together pieces of reusable code). –Compiled, so it’s faster than Java, but not cross platform. –Unlike Java, it allows full access to the operating system (including file access commands). This means that ActiveX components are potentially less-secure than Java (easier to spread viruses, deploy malicious programs).

10. Host / Terminal Model Dumb terminals typically display only text sent from host. They do not perform any computing & don’t have a microprocessor. PCs can run terminal programs to act like dumb terminals & access hosts. All programs & data are on the host (usually mainframe)

11. Client / Server Computing Client –a program which makes request of another program, usually on another computer (e.g. web browser) –requests data or other action from servers Server –a program (usually on another computer) that runs services that are shared among multiple client/users on a network (ex. E-mail server, web server, database server). –responds to client requests (delivers data, performs tasks)

12. Client / Server Model PC executes client code client code makes a request Server executes server code & responds to request, holds data sales accounting wheels chemicals Divide & Conquer Share & Share Alike

13. business logic palm pocket pc web data fat client (stored on local disk) N-tier Client/Server

16. Local offices “screen real estate” - localization Regional offices Trade regulations Global HQ Company-wide standards for service, Central database France Italy USA Mexico EU NAFTA Headquarters

17. Legacy Systems = IS Handcuffs Many firms have limited to no integration across geographic areas functional areas (v-chain) products, plants, & business units BuyersSuppliers

18. Linking Applications EDI – Electronic Data Interchange –Well established (X.12/EDIFACT) –Expensive over private networks, complex Package Applications –Fast to deploy, but limited to vendor offerings Web Services –A collection of technologies (an alphabet soup of tech standards & communications protocols) that together get computer programs to talk to one another. –XML, SOAP, UDDI, WSDL, …

21. southwestairlines.com dollar.com alamo.com hertz.com Inter-Firm Web Services