The recruiter computer will contain
the user services (EXE) and a copy of the business services (DLL's). This
system will depend on the data services (DLL's) which will be located on a
separate server. Also, note that the server will also include the Access
database. An applicant's computer will allow him/her to view information
through the web interface. In turn, the web interface will depend on the
web server to get its business services to interact with the data
services. The business services found on our web server will depend on the
data services.
The User Services Tier
The user services tier will be the component of the application that
will interact with the user by allowing the user to view and navigate
through the application as well as to add, edit, cancel and save the
information displayed on the form. This tier will show up as an executable
file (. exe) and will be presented on the user's computer in a physical
manner.
The Business Services Tier
The business services tier will be the business logic or business
rules. It is the tier that will interact between the user interface tier
and the data tier. In order for the user services tier to get information
from the data services tier, it must request this information from the
business services tier first. The business services tier will then access
the information from the data services tier and relay this information on
to the user services tier. This tier will be in the form of a dynamic link
library file (.dll) as well. The business services tier can also be
located on another computer, however, at this point, the business services
tier will be physically located on the same computer as the user services
tier.
The Data Services Tier
The data tier will be the place where the data will be stored. It can
be stored on a different computer or on the existing computer. In the case
of the Virtual Placement Agency, the data services tier will be located on
another computer in the form of a dynamic link library file (.dll) in a
physical manner. The Access database will be located on the data services
tier as well. |
