1. State any assumptions that you may have made. 2. You must draw the DFDs using a computer diagramming tool, you are suggested to use Microsoft Visio.The Task – System Requirement Modelling Using DFDs
You are required to complete all the following three components.
1) the business activities, and
2) the external entities (Sources/sinks)
as detailed in the narrative included below.
2. Draw the context diagram and the Level 0 DFD for National Merchandising.
3. Draw the Level 1 DFD that James (in the scenario) was tasked to do.
1. State any assumptions that you may have made.
2. You must draw the DFDs using a computer diagramming tool, you are suggested to
use Microsoft Visio.
You must submit your assignment in the Dropbox in CloudDeakin and it must include the
1. The assignment declaration page
2. Any assumptions you have made.
3. The list of business activities and list of external entities,
4. The context level diagram and the two DFDs
(1) a level 0 DFD
(2) a Level 1 DFD (done by the junior analyst, James)
Remember that late submissions will be penalised. Further, the DSO server is the ultimate time
keeper when it comes to determining whether your submission has been received on time. You
are also reminded to keep a backup copy for record.
National Merchandising receives invoices from its vendors by mail. Every morning the mailroom
manager, Ross Manning, delivers all invoices and all mail addressed to the attention of the
accounts payable department to Ginny Anderson, the accounts payable clerk, who accumulates
invoices throughout the week in an accordion folder. On Thursday, she reviews, prices and posts
Thursdays mornings, Ginny checks if the invoices were signed or not by the vendors, and if the
invoices were accepted or not by an authorized employee at National Merchandising. If they are
not, she mails the invoices back to the vendors with the corresponding reason(s). If the orders
are signed and were accepted she checks if a purchase order is on file. If it is she approves the
invoices. If there is no purchase order on file she sends the order to the purchase department for
approval. If the purchase department secures the approval of the invoice and sends it back to
accounts payable, Ginny files it with the other approved invoices. If the invoice is not approved
by the purchase department she mails it back to the vendor, again, with the corresponding
reason(s). Then, she verifies all price, shipping and handling, and tax computations, corrects the
totals as needed, files the corrected invoices in a payable invoices file, and enters the invoice
number and total in an invoice log file.
Thursdays afternoons, Ginny retrieves the invoices from the payable invoices file and adds the
amount due and invoice number to the vendor's ledger card -- a record of all accounting
transactions for the particular vendor -- and to the general ledger. Finally, she logs the accounts
payable transactions in the accounts payable file, using information from the invoice log file and
payable invoices file. The invoices themselves are stored alphabetically in a filing cabinet.
Checks for payments to vendors are written and signed each Friday. Harry Deming, manager of
accounts payable, review all accounts and outstanding invoices, and determines which ones
should be paid. He writes the check and at the same time enters the amount of the check, the
name of the vendor, and the numbers of the invoices paid, in the checkbook. The same
information is entered on the vendor's ledger card and the general ledger. The checks are sent in
one batch, with the appropriate invoices, to the controller, Ann Williams, who reviews and signs
each check. In some cases, she disapproves the payment and returns the check to Harry unsigned.
The signed checks are placed in individual envelopes and taken to the mailroom for mailing to
Ann Williams decided to have the accounts payable system automated. She had a meeting with
John Parkins, the MIS manager, and obtained his concurrence for developing the system. A
senior systems analyst, Carl Sagan, was assigned to act as a leader of the systems development
project. He interviewed Ginny, Harry and Ann and prepared the contextual (or high-level) and
the second-level DFDs, later approved by Ann.
It was also agreed that Ann's signature would be scanned and that the future system would print
the checks automatically, including Ann's signature. Sagan needs to explode the DFDs in a third
level of detail to complete the analysis. He assigned James, as junior system analysts, the task of
exploding the DFDs.