Patent Number: 
Section: claims

1. A method of assigning resources for a computer system design comprising:receiving desired levels of performance parameters for a computer system design from a user via a user interface to a computer system, the design including assignments of system resources to applications;modifying the design in response to said desired levels including modifying the assignments of the system resources;predicting levels of performance parameters for the modified design; anddisplaying for the user an indication of the predicted levels of performance parameters for the modified design via the user interface. 2. The method according to claim 1, wherein the computer system design comprises a design for a data storage system. 3. The method according to claim 1, further comprising reducing one or more of the performance parameters from said desired levels of performance parameters. 4. The method according to claim 3, wherein said reducing is based on at least one utility function representing utility as a function of one or more of the performance parameters. 5. The method according to claim 4, further comprising:receiving the at least one utility function via the user interface to the computer system; andstoring the at least one utility function in a memory device of the computer system. 6. The method according to claim 1, wherein the desired levels of performance parameters are specified by the user through a graphical user interface. 7. The method according to claim 1, wherein the desired levels of performance parameters are specified by the user through a graphical user interface by the user manipulating heights of bar graphs shown on a display of the computer system. 8. The method according to claim 7, wherein each bar graph indicates the corresponding desired level of the performance parameter. 9. The method according to claim 8, wherein each bar graph also indicates the corresponding predicted level of the performance parameter. 10. A method of assigning resources for a computer system design comprising:receiving desired levels of performance parameters for a computer system design from a user via a user interface to a computer system;developing the design including assignments of system resources to applications;predicting levels of performance parameters for the design;comparing the predicted levels of performance parameters to the desired levels of performance parameters;modifying the design including modifying the assignments of the system resources when the predicted levels are lower than the desired levels, said modifying being performed by the computer system; anddisplaying for the user results of the modifying via the user interface. 11. The method according to claim 10, wherein the computer system design comprises a design for a data storage system. 12. The method according to claim 10, wherein said developing comprises assigning system resources to applications to be served by the design. 13. The method according to claim 12, said assigning being performed by a design tool operating on the computer system. 14. The method according to claim 10, further comprising reducing one or more of the performance parameters from said desired levels of performance parameters. 15. The method according to claim 14, wherein said reducing is based on at least one utility function representing utility as a function of one or more of the performance parameters. 16. The method according to claim 15, further comprising receiving the at least one utility function via the user interface to the computer system. 17. The method according to claim 10, wherein the user interface is a graphical user interface. 18. The method according to claim 17, wherein the desired levels of performance parameters are specified by the user through the graphical user interface by the user manipulating heights of bar graphs shown on a display of the computer system. 19. The method according to claim 18, wherein each bar graph indicates the desired level of the corresponding performance parameter. 20. The method according to claim 19, wherein each bar graph also indicates the predicted level of the corresponding performance parameter. 21. The method according to claim 10, further comprising repeating said steps of predicting and comparing after said modifying. 22. The method according to claim 21, wherein when the predicted levels are lower than the desired levels after said modifying, then notifying the user. 23. An apparatus for assigning resources for a computer design system, comprising a computer programmed to operate in a first program loop in which a user specifies desired levels of performance parameters of the design, the design including assignments of system resources to applications, via a user interface and a second program loop in which: performance parameters are compared to the desired levels of performance parameters; the design is modified, including modifying the assignments of system resources to applications, in response to the comparison and results of the modifying are displayed for the user via the user interface. 24. The apparatus according to claim 23, wherein the computer system design comprises a design for a data storage system. 25. The apparatus according to claim 23, wherein one or more of the performance parameters is reduced from said desired levels of performance parameters based on at least one utility function representing utility as a function of one or more of the performance parameters. 26. The apparatus according to claim 25, wherein the at least one utility function is specified by the user. 27. The apparatus according to claim 23, wherein the desired levels of performance parameters are specified by the user through a graphical user interface. 28. The apparatus according to claim 27, wherein the desired levels of performance parameters are specified by the user through the graphical user interface by the user manipulating heights of bar graphs shown on a display of the computer system. 29. The apparatus according to claim 28, wherein each bar graph indicates the desired level of the corresponding performance parameter. 30. The apparatus according to claim 29, wherein each bar graph also indicates the predicted level of the corresponding performance parameter.