: Supporters of Object-0riented technology for software development typically state reliability among the key benefits of adopting Object-Oriented tools, techniques, and languages. In the traditional Software Engineering view of reli- ability, little research or real world confirmation provides substantiation to such claims of enhanced reliability as a by-product of following Object-Oriented Software Development methods. The contention of this paper is that devel- oping Object-Oriented software systems using Object-Oriented Analysis and Object-Oriented Design methods with Use Cases can provide significant advantages in measuring reliability. Jacobson’s Use Cases and Musa’s Opera- tional Profiles are discussed after a consideration of the theoretical validity of merging a method of quantification rooted in non-Object-Oriented system development and research. For readers unfamiliar with Software Reliability Engineering a brief discussion of terms and concepts precedes the discussion of why Operational Profiles and Use Cases lay on parallel and complimentary tracks of development methodology. Finally, an example from Jacobson’s text on Use Cases offers the basis of a demonstration on how an Operational Profile could be grafted onto an existing Object-Oriented analysis solution. EXTENDING JACOBSON USE CASES TO QUANTIFY OPERATIONAL PROFILES FOR SOFTWARE RELIABILITY James Cusick j.cusick@computer.org July 15, 1994 ABSTRACT