Ryerson Polytechnic University

Midterm Examination

CBIS504 Winter 1999

Suggested Solution

 

Question 1

 

 

The computer processing portion of a Sales Order system is represented by the a flowchart in the text Answer the following questions:

 

a. What type of data processing system is this? Explain and be specific. (5)

 

Response: This is a batch processing system which uses direct access storage devices rather than sequential tapes, but the records are stored in sequential files. The transactions are keyed in, and the batch totals are calculated. The batch totals accompany the sales order file through all the data processing runs that follow. The edit run is used to test each record for the existence of clerical or logical errors. Any records with errors are removed and written to an error file to be corrected later by an authorized person. The batch totals are recalculated for the "clean" transactions. The edited file is then sorted based on the primary customer account number. The batch totals are used to verify the integrity of the sorted database file. The sorted file is used to update the accounts receivable file. The original accounts receivable file remains in tact and is used for backup. The newly created accounts receivable becomes the new master file. The customers' invoices are processed during the update and billing run. The sales order file is sorted on the inventory number so that the inventory master file can be updated. The original inventory file remains in tact and is used for backup. The newly created inventory file becomes the new master file. The batch totals are still used to verify the completeness and accuracy of the transaction file. At the end of the day, the batch totals are sorted and used to update the general ledger. The original general ledger remains in tact and is used for backup. The newly created general ledger becomes the new master file.

 

b. The auditor suggests that this system can be greatly simplified by changing to direct access files, explain the major operational changes that would occur in the system if this were done.(5)

 

Response: If the sequentially stored data files are not used and real‑time processing of data using indexed direct access files are used instead, the editing and sort runs no longer become necessary. The transactions will be immediately checked for input errors, and the accounts receivable file and inventory files will automatically be updated as each transaction is processed. Thus, batch totals will no longer be used. Accumulators may be used to accumulate values which are periodically posted to the general ledger. The accounts affected by each transaction in the master file will be overwritten with each transaction that is processed.

 

c. The auditor warns of control implications from this change that must be considered. Explain the nature of the control implications.(5)

 

Response: Since the computers will be performing tasks that individuals used to perform, such as inventory controls, the control procedures over program code need to be secured from unauthorized access. The master files are overwritten each time a record is processed. Controls should be put into place for periodically making a backup copy of the master file, so that the records may be covered in case the current working copy of a master file is destroyed or incorrectly overwritten.

 

d.         Sketch a flowchart (the computerized portion only) of the proposed new system. Use correct symbols and label the diagram. (10)


 


Response: See diagram on the following page.

 

Question 2

 

2.   Examine the diagram in the text and indicate any incorrect initiation andlor

transfer of documentation. What problems could this cause. (25)

 

Response: The purchase requisition should originate from the inventory control department after someone has reviewed the records to determine if and how much of an inventory item needs to be ordered. If purchasing agents are allowed to authorize purchase requisitions, they might be tempted to buy items not needed in order to reap benefits and/or kickbacks from the vendor. The purchase order which is sent to receiving is not indicated as a "blind copy", and this might cause employees to either shirk their responsibilities and not count the inventory or to steal some units since they know their value. Further, receiving should retain a copy of the receiving report in their files along with the purchase order and packing slip. The inventory control department should not prepare a journal voucher to send to the general ledger department, rather they should prepare summary information which the general ledger department can use to reconcile the inventory control account with inventory subsidiary summary. The accounts payable department needs to post the liability to the accounts payable subsidiary ledger. The subsidiary accounts payable ledger will not balance with the control account in the general ledger if these postings are not made.

 

Question 3

 

3.  Design a relational data base system for a large costume rental store. The store

has approximately 3,200 customers each year. It is stocked with over 500

costumes in various sizes. The rental costumes and other items which may be

purchased by the customer (e.g., make‑up and teeth) are purchased from

approximately 35 different suppliers. Design the necessary data base files. Make

sure they are in third normal form, and indicate the linkages necessary.

 

Response: Following is a list of database files unique to this type of business. Additionally, traditional accounting files would be necessary. The key fields used for linking are in boldface.

 

Costume Master       Costume Invento                      Customer Master                      Vendor Master

Costume BD Number                                              Costurne BD Number              Customer BD Number Vendor BD Number

Description             Copy Number                          Last Name                               Company Name

No. of Costumes       Purchase Date                         First Name                               Addressl

No. of times rented  size                                          Middle Initial                           Address2

No. of times rented‑past year No. of times rented     AddressI                                   city

Vendor BD Number Last date rented                      Address2                                  State

                                Status‑checked out                  city                                           Zip code

                                                                                State

                                                                                Zip Code

                                                                                Last date rented a costume

 

Opgn Costume Transaction Lpg                                                              Closed Costume Transaction. Locl           Fine Loc

Customer BD Number             Customer ]D Number                              Customer BD Number

Costume BD Number               Costume BD Number                              Transaction Number

Copy Number                           Copy Number                                          Amount Due

Date Rented                             Date Rented                                            Amount Paid

Date Due                                  Date Due                                                 Date Paid

Transaction Number                Transaction Number

                                                Date Back

 

Sundries Invento      Sundries Transaction Lo‑q

Item Number            Item Number

Description              Quantity

Quantity on Hand     Date sold

EOQ

Safety Stock

 

 

Question 4

 

Response:

a. By integrating microcomputers with the company's mainframe, the Milok Company should be able to realize the following enhancements to information and report processing.

·                     Processing advantages. Routine, non‑routine, large and small analyses can be completed by using the microcomputer with a typed copy as output. This eliminates manual preparation and reduces the time required to prepare and summarize reports. Furthermore, the typed output is more professional.

·                     Data input. Data is transferred from computer to computer at very high speed and accuracy rather than using a clerical data entry via a keyboard. Downloading also eliminates any duplicate entry of data on two or more systems.

·                     Changes and sensitivity analysis improved. Once a spreadsheet or database report is set up/programmed, the effect of data changes or what‑if alterations can be incorporated very quickly. The slow and inherently error‑prone function of manual recalculation is eliminated because computer instructions are saved and can be repeated.

·                     Data reusability. Because the data is downloaded onto a disk, it can be reused in its unaltered form without going back to the mainframe. This can improve presentation and decision activities.

·                     Customization of output. A microcomputer user can develop templates or small program routines (also called macros) with a database or spreadsheet package to automate report generation. This facility, which is normally done by a programmer on a mainframe, can free the programmer for other work. This also speeds report distribution and allows for the presentation of only relevant data.

 

b. By integrating microcomputers with a mainframe computer, computer resource utilization will be altered in the following areas.

·                     Special requests. Nonroutine, one‑time reports can be done by a user rather than by a special systems request. This resource reallocation is dependent on the amount of data.

·                     Programmer utilization. Programmers will be freed from programming and maintaining users' requests and allowed to focus on complete system or user department areas, which form the base for users.

·                     Hardware usage and availability. For the people involved with a micro/mainframe configuration, the role of the mainframe will change from data storing, processing, and delivering to greater emphasis on storing and delivering. A significant amount of processing can be done on the microcomputer. This may or may not decrease the load on the mainframe as the environment will begin to look more like real time rather than batch processing. Such peripherals as terminals and high‑speed printers may be less needed as microcomputer equipment is comparable in price and provides more utilization.

·                     Technical support. The technical support function will need to be reviewed. Developments in both the mainframe and microcomputer world must be monitored. System relations with users must be cultivated as the systems department will take on a consulting/instructing responsibility.

·                     Systems and report development. Through hands‑on experience, microcomputer users will communicate better with the systems department. New systems can be designed by the users on a small scale. This will give the user/requester a more intimate knowledge of the system's requirements which should make for a clearer, tighter specification.

 

c. The use of a micro‑to‑mainframe link will greatly reduce the security of the original data stored on the mainframe as follows.

·                     Because of the nature of microcomputers, there will be a general loss of centralized control such as that previously associated with the operation of a mainframe.

·                     Floppy disks can be picked up and pocketed either accidentally or intentionally.

·                     Because of their nature, microcomputers are more accessible than terminals; therefore, a microcomputer connected to another computer increases the risk of unauthorized access to the other computer's data. Database administration and password hierarchy and control must be more sophisticated and stricter to service the wider uses of the system

·                     Data could be downloaded from the mainframe to the microcomputer, altered/ manipulated on the microcomputer, and then passed back to the mainframe. Thus, the original data on the mainframe could be changed. Without proper controls there might be no audit trail and no way to detect what was done and by whom.