344 Part III • Acquiring Information Systems
Vendor Invoice
Arrives
Record in
Payables File
Process
Summaries
Reconcile
Invoice with
Receipts
Create New
Vendor
Account
Resolve or
Reject
Unapproved
Invoice
Senior Clerk
Determines
Amount to Be
Paid
Make Check
Record
Payment
Mail Check
Vendor
Receives
Check
Purchase
Order File
Receipts
File
Invoice
Approved?
No
No
No
No
Yes
Yes
Yes
New
Vendor?
Summary
Payables
Report to
Accounting
Payables Within
Net Term?
Invoices/
Payables
File
FIGURE 8.12 Work Process Flow Diagram for Accounts Payable
Techniques for the Logical To-Be Model
In this step, systems developers build a high-level model
of a nonexistent system: the system that the users and
managers would like to replace the one they have now.
The Logical To-Be model is an abstraction that identifies
the processes and data required for the desired system
withoutreference to who does an activity, where it is
accomplished, or the type of computer or software used.
The model describes the “what,” rather than the “how.”
Stated differently, it separates the information that moves
through the business process from the mechanisms that
move it (e.g., forms, reports, routing slips). This is impor-
tant because IT enables information to be in more than
one place at the same time; paper does not possess this at-
tribute. By leaving physical barriers behind, the analyst
can better determine how to exploit IT. This abstraction
step can be difficult for first-time business participants
because it appears to ignore issues crucial to their daily
work (e.g., specific forms, reports, routing slips).
Understanding that the Logical To-Be model encompass-
es information flows, rather than physical flows (i.e., of
paper, money, products), is the key.