Guidelines: Business Actor
Topics
To fully understand the purpose of a business you must know who
the business interacts with; that is, who puts demands on it, or is
interested in its output. The different types of "interactors" are
represented as business actors.
The term actor means the role someone, or something plays while interacting
with the business. The following types of business users are examples of
potential business actors:
- Customers
- Suppliers
- Partners
- Potential customers (the "market place")
- Local authorities
- Colleagues in parts of the business not modeled.
Hence, an actor normally corresponds to a human user. However, there are
situations where, for instance, an information system plays the role of an
actor. If your bank's on-line services are so good that your business can
manage most of its bank transactions from a PC on your own premises, your use
cases interacting with the "money supplier" actor, the bank, will in
fact interact with an information system.
An actor represents a particular type of business user rather than a real
physical user. Several physical users of a business can play the same role in
relation to it; that is, they act as instances of one and the same actor.
Also, the same user can act as several different actors. This means that one and
the same person can embody instances of different actors.
A business actor should be given a name that reflects its role towards the
business. The name should be applicable to any person-or any information
system-playing the role.
The characteristics of a business actor should cover the following
topics:
- Prior knowledge and experience.
- Physical characteristics.
- Social and physical environment.
- Job, tasks, and requirements.
- Cognitive characteristics.
This information is useful to define the business use cases in a way that is
meaningful to the business actor. It is only relevant for "human"
business actors.
- All actors are found. Everything in the business environment interactions-both
human and mechanical-is modeled with actors. You cannot be sure of finding
every actor until you have found and described every use case.
- Each human actor expresses a role, not a specific person. You should be
able to name at least two persons that can play the role of each actor. If
you can't, you may have modeled a person, not a role. Of course, there are
situations in which you can find only one person who can play a role.
- Each actor models something outside the business.
- Each actor is involved with at least one use case. If an actor does not
interact with at least one use case, you should remove it.
- A specific actor does not interact with the business in several completely
different ways. If an actor interacts in several completely different ways,
you have probably assigned several roles to one actor. In that case, you
should split the actor into several actors, each representing a different
role.
- Each actor has an explanatory name and description. An actor's name
should represent the role it plays in relation to the business. The name
must be understandable to people outside the business-modeling team.
| |
|