Generalized Timelines API is a computer program that provides (1) a means of representing arbitrary realworld state and resource information for use in planning, scheduling, and plan- and schedule-executing software and (2) an application-programming interface (API) that accelerates the development and validation of the software. In prior time-line programs, constraints had not been regarded as parts of time lines, and it was difficult to represent constraints. For the present program, a time line is defined as a representation of the actual and/or predicted value(s) of a variable and a set of constraints on the variable, both at successive intervals of time. The program (1) enables assignment of values to variables and modeling of the constraints on the variables, all as functions of time; (2) makes it possible to determine whether the values are consistent with the constraints; and (3) provides “hooks” to the search space represented by the variables for the purpose of optimizing plans. This program enables computer-programming specialists to engage in research on, and development of, scheduling application programs separately from the efforts of other specialists to implement time lines specific to their domains of expertise. In comparison with prior software of the same type, this program is representationally sufficient for more domains.

This program was written by Steve Chien, Russell Knight, Kim Gostelow, Tom Starbird, Gregg Rabideau, and Robert Sherwood of Caltech for NASA’s Jet Propulsion Laboratory.

This software is available for commercial licensing. Please contact Don Hart of the California Institute of Technology at (818) 393- 3425. Refer to NPO-21022.