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第八章迷你案例之解答

1. The purpose of the TEXTBOOK INVENTORY SYSTEM at a campus bookstore is to supply textbooks to students for classes at a local university. The university’s academic departments submit initial data about courses, instructors, textbooks, and projected enrollments to the bookstore on a TEXTBOOK MASTER LIST. The bookstore generates a PURCHASE ORDER, which is sent to publishing companies supplying textbooks. Book orders arrive at the bookstore accompanied by a PACKING SLIP, which is checked and verified by the receiving department. Students fill out a BOOK REQUEST that includes course information. When they pay for their books, the students are given a SALES RECEIPT.

2. The purpose of the PLANT SCIENCE INFORMATION SYSTEM is to document the study results from a wide variety of experiments performed on selected plants. A study is initiated by a researcher who submits a RESEARCH PROPOSAL. After a panel review by a group of scientists, the researcher is required to submit a RESEARCH PLAN AND SCHEDULE. A FDA RESEARCH PERMIT REQUEST is sent to the Food and Drug Administration, which sends back a RESEARCH PERMIT. As the experiment progresses, the researcher fills out and submits EXPERIMENT NOTES. At the conclusion of the project, the researcher’s results are reported on an EXPERIMENT HISTOGRAM.

Process Modeling 9-2

3. The purpose of the production scheduling system is to respond to a PRODUCTION ORDER (submitted by the SALES DEPARTMENT) by generating a daily PRODUCTION SCHEDULE, generating RAW MATERIAL REQUISITIONS (sent to the MATERIALS MANAGEMENT DEPARTMENT) for all production orders scheduled for the next day, and generating JOB TICKETS for the work to be completed at each workstation during the next day (sent to the SHOP FLOOR SHIFT SUPERVISOR). The work is described in the following statements. The production scheduling problem can be conveniently broken down into three functions: routing, loading, and releasing. For each product on a PRODUCTION ORDER, we must determine which workstations are needed, in what sequence the work must be done, and how much time should be necessary at each workstation to complete the work. This data is available from the PRODUCTION ROUTE SHEETS. This process, which is referred to as ROUTING THE ORDER, results in a ROUTE TICKET. Given a ROUTE TICKET (for a single product on the original PRODUCTION ORDER), we then LOAD THE REQUEST. Loading is nothing more than reserving dates and times at specific workstations. The reservations that have already been made are recorded in the WORKSTATION LOAD SHEETS. Loading requires us to look for the earliest available time slot for each task, being careful to preserve the required sequence of tasks (determined from the ROUTE TICKET). At the end of each day, the WORKSTATION LOAD SHEETS for each workstation are used to produce a PRODUCTION SCHEDULE. JOB TICKETS are prepared for each task at each workstation. The materials needed are determined from the BILL OF MATERIALS data store, and MATERIAL REQUESTS are generated for appropriate quantities.

Copyright © 2004 by McGraw-Hill Companies, Inc. All rights reserved.




4. Policyholders must submit an EXPLANATION OF HEALTH CARE BENEFITS (EOHCB) along with proof that their primary health policy claim has been paid. All CLAIMS are mailed to the claims-processing department.

CLAIMS are initially sorted by the claims screening clerk. This clerk returns all requests that do not include the EOHCB. For those requests returned, a PENDING CLAIM is created, dated, and stored by date. Once each week, the clerk deletes all tickets that are more than 45 days old and sends a letter to the policyholders notifying them that their case has been closed. Requests that include the EOHCB are then sorted according to type of claim. Requests that include an EOHCB REFERENCE NUMBER are matched up with an EOHCB form, which is pulled from the OPEN CLAIMS file. At the end of each day, all these claims are forwarded to the preprocessing department.

In the preprocessing department, clerks screen the EOHCB for missing data. They complete the form if possible. Otherwise, a copy of the claim is returned to the policyholder with a letter requesting the missing data. The original EOHCB is placed in the OPEN CLAIMS file, and a PENDING CLAIM is sent to the claims screening clerk. Completed claims are assigned a claim number, and the claim is microfilmed and filed for archival purposes.

A different clerk checks to see if the PROOF OF PRIMARY HEALTH CARE POLICY PAYMENT was included or is on file in the PRIMARY PAYMENT file. If it is not available, the policyholder is sent a letter requesting the proof. The EOHCB is placed in a PENDING PROOF file. Claims are automatically purged if they remain in this file for more than 14 days (a letter is sent to policyholders whose claims have been purged).

If proof is available, another clerk pulls the policyholder’s policy record from the POLICY file, records policy and action codes on the EOHCB, and re-files the policy. At the end of the day, all preprocessed claims are forwarded to Information Systems.



5. The purpose of the GREEN ACRES REAL ESTATE SYSTEM is to assist agents as they sell houses. Sellers contact the agency, and an agent is assigned to help the seller complete a LISTING REQUEST. Information about the house and lot taken from that request is stored in a file. Personal information about the sellers is copied by the agent into a sellers file.

When a buyer contacts the agency, he or she fills out a BUYER REQUEST. Every two weeks, the agency sends prospective buyers AREA REAL ESTATE LISTINGS and an ADDRESS CROSS-REFERENCE LISTING containing actual street addresses. Periodically, the agent will find a particular house that satisfies most or all of a specific buyer’s requirements, as indicated in the BUYER’S REQUIREMENTS STATEMENT distributed weekly to all agents. The agent will occasionally photocopy a picture of the house along with vital data and send the MULTIPLE LISTING STATEMENT (MLS) to the potential buyer.

When the buyer selects a house, he or she fills out a OFFER that is forwarded through the real estate agency to the seller, who responds with either an OFFER ACCEPTANCE or a COUNTEROFFER. After an offer is accepted, a PURCHASE AGREEMENT is signed by all parties. After a PURCHASE AGREEMENT is notarized, the agency sends an APPRAISAL REQUEST to an appraiser, who appraises the value of the house and lot. The agency also notifies its finance company with a FINANCING APPLICATION.

EVENT LIST

Event DescriptionTrigger (Inputs) Responses (Outputs)

Seller enters into agreement to have agency sell house.

Listing Request Create Listing

Create Seller

Buyer initiates contact with agency about buying a home.

Buyer Request Area Real Estate Listing

Address Cross-Reference

Multiple Listing Statement

Buyer’s Requirement Statement

Buyer makes offer on house. Offer Offer Document

Seller accepts buyer’s offer. Purchase Agreement Notarized Purchase Agreement

Seller makes counteroffer to seller.

Counteroffer Counteroffer document

Agency sends a request to a appraiser to have house appraised.

Appraisal Request Appraisal of House report

Agency notifies financial company of opportunity to finance house.

Financing Application Financing Program Offer



6. The purpose of the OPEN ROAD INSURANCE SYSTEM is to provide automotive insurance to car owners. Initially, customers are required to fill out an INSURANCE APPLICATION. A DRIVER’S TRAFFIC RECORD REQUEST is requested from the local police department. Also, a VEHICLE TITLE AND REGISTRATION is requested from the Bureau of Motor Vehicles. PROPOSED POLICIES are sent in by various insurance companies who will underwrite those policies based on a quoted fee. The agent determines the best policy for the type and level of coverage desired and gives the customer a copy of the INSURANCE POLICY PROPOSAL AND QUOTE. If the customer accepts, he or she pays the INITIAL PREMIUM and is issued both the policy and a state-required INSURANCE COVERAGE STATEMENT (a card to be carried at all times when driving a vehicle). The customer information is now stored. Periodically, a PREMIUM NOTICE is generated, which—along with POLICY COVERAGE CHANGES—is sent to the customer, who responds by sending in a PREMIUM after which new INSURANCE COVERAGE STATEMENTS ARE ISSUED.Both a vehicle owner and the insurance company are required to provide annual PROOF

OF LIABILITY INSURANCE to the Bureau of Motor Vehicles.



Answer continued on next page.



Answer continued on next page.



7. Initially, Postal Service trucks bring tax returns to the regional center. The envelopes are then sorted by type of return—for example, long form versus short form and whether or not the envelope contains a payment. The sorted envelopes are sent to Receipt and Control, where they are further separated into 27 types falling into three general categories: short forms requesting refunds, long forms requesting refunds, and returns containing tax payments.The documents are sorted twice because of the sheer volume of the returns. It’s not

unusual for the IRS to receive more than 200,000 returns in one day. The first sort divides that total to make the job more manageable.Why so many types? Some returns are requests for extensions for filing. Others are

quarterly estimated tax payments. There are over 500 official government forms for filing tax returns!For example, in order to process short forms requesting refunds, operators submit

forms to a machine that scans the returns and stores the data for later processing. The data is read by the main computer. It determines the correct tax, decides whether a refund should be sent, updates taxpayers’ files, and prints letters, notices, liens, etc.The refund information is sent to the National Computing Center, which subsequently

triggers the Treasury Department to issue the actual refund checks. Letters, notices, and other communications are sent to local IRS sites around the country, from which appropriate information is sent to taxpayers.The processing of long forms requesting refunds is similar, but not identical, to the

processing of the short forms because the long forms usually include multiple schedules of information, such as itemized deductions. First, returns are sorted into blocks of batches to be processed as single units. Batches are numbered to ensure that no returns are lost or excessively delayed. The batches are then forwarded to examiners. The examiners check for and correct errors and code the returns for processing.The examiners send back to the taxpayers any returns with incomplete or

uncorrectable data. Also, clerks stamp a document locator number on each return for



additional tracking capability as the return moves through the system. From this point, the processing is similar to the short form. Returns are input to the computer system. Data is stored for subsequent processing. The data is read by the main computer. It determines the correct tax, decides whether a refund should be sent, updates taxpayers’ files, selects returns for possible tax audits, and prints letters, notices, liens, etc. Refund information is sent to the National Computing Center, which subsequently triggers the Treasury Department to issue the actual refund checks. Notices and information regarding audits are sent to local IRS sites around the country, from which appropriate information is sent to taxpayers.For returns containing tax payments, examiners check for and correct errors, code the

returns for processing, and send back to taxpayers any returns with incomplete or uncorrectable data. Returns are entered into the computer. The computer checks taxpayer calculations and amounts, assigns document locator numbers, and stores the data. Then, the preceding steps are repeated using different operators.The data from the second operators is checked against the first set for accuracy. Error

reports are sent to examiners. Accurate data is stored for subsequent processing. Checks are collected for daily deposit into the Federal Reserve Bank.Examiners check for errors, correcting any errors they can, and write the taxpayers for

any missing information. At this point, the returns follow identical processing as described for the long forms requesting refunds.Draw the logical data flow diagram for the physical description.

ANSWER:

The narrative is replete with opportunities for interpretation. Also, we don’t know what details may have been left out or misinterpreted by the author.

To draw the logical DFD, we must effectively strip out the bureaucratic, physical, implementation details in the narrative. Sorting, routing, duplicate data entry, and other such details represent the way the system is physically implemented. The following logical DFD represents one interpretation of the essence of the system.

Note: Like the students, we had to make some assumptions (as noted in parentheses on the diagram.)

(Continued on next page.]





8. First, notice how cryptic the narrative got. Ironically, the more we tried to clarify the narrative, the longer the narrative got and the more cryptic it seemed. Obviously, there is some room for interpretation here, but the following decision table reflects the intended policy:

Condition A --- the students total score for the first 3 assignments or exams:A = 90-100B = 80-89C = 70-79D = 60-69F = 0-59

Condition B --- the students score for the fourth assignmentP = 70-100N = 0-69

Condition C --- number of absencesA = 0-3U = 3+

1 2 3 4 5 6 7 8 9 10

11

12

13

14

15

16

17

18

19

20

Cond A A B C D F A B C D F A B C D F A B C D F

Cond B P P P P P N N N N N P P P P P N N N N N

Cond C A A A A A A A A A A U U U U U U U U U U

Grade A X

Grade B X X

Grade C X X

Grade D X X

Grade F X X X X X X X X X X X X X

There are no undefined rules in this grading policy. Had there been undefined rules in this policy, those rules would have represented grading loopholes that could be used against the instructor. The instructor would need to determine how to handle those rules or make it impossible for that combination of conditions to occur. The simplified decision table follows:

1 2 3 4 5 6 7 8 9 10

Cond A A B C D F -- A B C D

Cond B P P P P P N P P P P

Cond C A A A A -- -- U U U U

Grade A X

Grade B X X

Grade C X X

Grade D X X

Grade F X X X



9. The answer to the poker chip problem is illustrated in the following decision table.

1 2 3 4 5 6 7 8Joe W W W W B B B B

Gordon W W B B W W B B

Susan W

B

W

B

W

B

W

B

Impossible–the were only two WHITE chips

X

Seeing both WHITE chips, Joe would have known his was BLACK. Obviously, he did not see this.

X

Seeing both WHITE chips, Gordon would have known his was BLACK. Obviously he did not see this.

X

Because Susan requested her blindfold NOT be removed, we could not evaluate this rule; therefore, it is still POSSIBLE

?

This is the critical rule! By eliminating the possibility of this rule (which would have meant her chip was WHITE, Susan knew her chip was BLACK because …

??

… all of these remaining rules result in an answer of BLACK! That’s why Susan was absolutely certain her chip was BLACK.

X X X X

So how did Susan eliminate Rule 7 as a possibility? Because neither Joe nor Gordon could have seen two WHITE chips, hers could not possibly be WHITE. Thus, because all remaining combinations result in her chip being BLACK, it must be BLACK!


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