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Problems

19 January, 2016 - 12:35

1.

Prepare a narrative to describe the system depicted in the physical DFD in Figure 2.15.

2.

Prepare a narrative to describe the system depicted in the logical DFD in Figure 2.16.

3.

Prepare a narrative to describe the system depicted in the flowchart in Figure 2.17.

4.

a.

List the entities and activities in Figure 2.17.

 

b.

Prepare a statement for each entity-relationship pair in Figure 2.18. (There are six pairs.) Each statement should explain the relationship category (e.g., “N-to-1,” “1-to-N,” “1-to-1,” etc.). For example, to describe the order customer relationship in Figure 2.9, we might say: “Orders are received from customers. A customer may place many orders (N) but each order is from only one customer (1), an N-to-1 relationship.”

 
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Figure 2.15 Physical DFD for Problem 2-1 
 
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Figure 2.16 Logical DFD for Problem 2-2 
 

APPENDICES 2A AND 2B.

Problems 5 through 8 are based on the following two narratives. Lincoln Company describes sales and credit card billing systems. Bono Insurance describes an automobile insurance order entry and billing system. For those who wish to test their documentation skills beyond the problems below, there are narratives at the end of Chapters 10 through 12. Note that for the Lincoln case we do not discuss, and you should ignore, the handling of cash received at the time of a sale.

Lincoln Company

The Lincoln Company operates pet supply stores at many locations throughout New England. The company’s headquarters are in Boston. The company accepts cash and its own Lincoln charge card (LCC). LCC billing and the treasury functions are located at headquarters.

At each store a customer presents the item(s) to be purchased along with cash or a LCC. Sales clerks prepare LCC slips and then all sales—cash and charge—are keyed into the cash register. At the end of the shift, the clerk forwards the LCC slips to the store cashier (again, as noted above, ignore the handling of the cash). The store cashier batches the LCC slips and sends the batches to the cash receipts department in Boston at 5:00 p.m. each day.

As each sale is keyed in by the sales clerks, Lincoln’s central computer system captures the data and stores them on a disk (“sales data”). Each night, the computer prints a sales report summarizing each store’s sales data. On the following morning, the sales report is sent to the cash receipts department, where the LCC slips for each store are reconciled to the line on the sales report that totals LCC sales for that store. The LCC slips are then sent to Lincoln’s IT division, where data preparation clerks scan the LCC slips to record the charges on a disk (“credit sales data”). At 9:00 p.m. each evening, the disk containing the credit sales data is e-mailed as an attachment to the computer room, where it is used to update the accounts receivable master data (also on disk). Each month, the computer prepares customer statements that summarize the LCC charges, and sends the statements to the customers.

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Figure 2.17 Flowchart for Problem 2-3 
 
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Figure 2.18 Entity-Relationship (E-R) Diagram for Problem 2-4 
 

Bono Insurance

The Bono Insurance Company of Needham, Massachusetts, processes its automobile insurance policies on a batch-oriented computer system. Customers send requests for auto insurance into the Needham sales office where sales clerks prepare policy request forms. These documents are forwarded to the input preparation department where data entry clerks use networked PCs to key and key-verify the data contained on the documents to a disk (“policy events”).

Each evening, the computer operations department retrieves the policy events data from the network and edits the data on the computer and then sorts the data in policy number sequence. Events data that do not pass the edits are deleted from the events data disk and printed on an error report. The error report is sent to the sales office where sales clerks review the report, correct the errors (contacting the customer, if necessary), and prepare another policy request form. These forms are submitted to data preparation each day along with other policy request forms.

In addition to the error report, the computer also prints a summary report listing the good events data. This report is sent to the sales office where the sales clerks compare the report to the copy of the policy request form that they had previously filed. If everything checks out, they notify computer operations to go ahead with processing. When notified, computer operations processes the correct events data against the policyholder master data to create a new policy record. Each evening, a disk, which was created during the processing run, is used to print premium notices that are sent to the customer.

5.

a.

Prepare a table of entities and activities based on either the Lincoln Company or the Bono Insurance narrative.

 

b.

Construct a context diagram based on the table you prepared in part a.

6.

Prepare a physical DFD based on the output from Problem 5.

7.

a.

Prepare an annotated table of entities and activities based on the output from Problem 5 and Problem 6. Indicate on this table the groupings, bubble numbers, and bubble titles to be used in preparing a level 0 logical DFD.

 

b.

Prepare a logical DFD (level 0 only) based on the table you prepared in part a.

8.

Construct a systems flowchart based on the narrative and the output from Problems 5 through 7.

9.

A description of fourteen typical information processing routines is given here, along with ten numbered excerpts from systems flowcharts (Figure 2.19).

 

Match the flowcharting segments with the descriptions to which they correspond. Four descriptions will be left blank.

 

a.

Data on source documents are keyed to an offline disk.

 

b.

A deposit slip and check are sent to a customer.

 

c.

A printed output document is filed.

 

d.

Output is sent to a computer screen at a remote location.

 

e.

A clerk manually posts sales orders to the outstanding order data store.

 

f.

A report is printed from the contents of a master data store.

 

g.

Data stored on a disk is sorted and placed on another disk.

 

h.

Data on a magnetic tape are printed during an offline operation.

 

i.

Data are keyed from a terminal at a remote location.

 

j.

A batch total is compared to the total reflected on an error and summary report.

 

k.

Magnetic tape input is used to update master data kept on a disk.

 

l.

The cash receipts summary report is sent by the accounts receivable department to the general ledger department.

 

m.

Input stored on two magnetic disks is merged.

 

n.

Programmed edits are performed on key input, the data entry clerk investigates exceptions and keys in corrections, then the master file is updated.

 
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Figure 2.19 Flowchart Segments for Problem 2-9 
 

APPENDIX 2A P2-10 Refer to Figure 2.13, the level 0 DFD of Causeway’s cash receipts system.

a.

Construct a diagram 1, which “explodes” process 1.0, “Capture cash receipts,” down to the next level.

b.

Construct a diagram 2, which “explodes” process 2.0, “Record customer collections,” down to the next level.

c.

Construct a diagram 3, which “explodes” process 3.0, “Prepare deposit,” down to the next level.

d.

Construct a diagram 4, which “explodes” process 4.0, “Prepare cash receipts total,” down to the next level.