<Li> Extension: "a condition that results in different interactions from...the main success scenario". An extension from main step 3 is numbered 3a, etc . </Li> <P> The Fowler style can also be viewed as a simplified variant of the Cockburn template . </P> <P> A use case defines the interactions between external actors and the system under consideration to accomplish a goal . Actors must be able to make decisions, but need not be human: "An actor might be a person, a company or organization, a computer program, or a computer system--hardware, software, or both ." Actors are always stakeholders, but not all stakeholders are actors, since they "never interact directly with the system, even though they have the right to care how the system behaves ." For example, "the owners of the system, the company's board of directors, and regulatory bodies such as the Internal Revenue Service and the Department of Insurance" could all be stakeholders but are unlikely to be actors . </P> <P> Similarly, a person using a system may be represented as different actors because of playing different roles . For example, user "Joe" could be playing the role of a Customer when using an Automated Teller Machine to withdraw cash from his own account, or playing the role of a Bank Teller when using the system to restock the cash drawer on behalf of the bank . </P>

What do you mean by actors in use case methodology
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