accountinginformationsystems

1、SOLUTIONS FOR CHAPTER 4Discussion QuestionsDQ4-1"Data flow diagrams and flowcharts provide redundant pictures of an information system. We don't need both." Discuss.ANS.Logical data flow diagrams (DFDs) present only the logical elements of an information system. By excluding the physic

2、al elements, the logical DFD allows us to concentrate on what a system is doing without being distracted by how the functions are being performed and by whom.Physical DFDs present the physical elements of an information system. They concentrate on who is acting on the data flowing through the system

3、. Physical DFDs allow us to concentrate on the entities involved in processing information. We can also see how much “work” is done by an entity by observing the flows into and out of an entity and whether those flows change names, an indication that they have been transformed within the entity.Fina

4、lly, a flowchart presents the logical and the physical details of a system's functions. It shows the details of how a process is accomplished and also shows the organizational unit that performs the process. As we will see in Chapter 9, these details are necessary to permit evaluation of a syste

5、m's controls. Also, systems flowcharts describe exception and error routines, which DFDs do not. DFDs concentrate on usual and recurring events.In conclusion, it is only with all of these diagrams that we can get a complete picture of a process. As noted above, however, each diagram has it funct

6、ion and, depending on our purpose, all may not be needed.DQ4-2"It is easier to learn to prepare data flow diagrams, which use only a few symbols, than it is to learn to prepare flowcharts, which use a number of different symbols." Discuss.ANS.Compare the DFD symbols in Figure 4.1 to the fl

7、owcharting symbols in Figure 4.6 and you probably conclude that it is quite easy to learn the DFD symbols. Also, examine Figure 4.7 and see that there are several standard routines used in flowcharts. Also, we believe that constructing DFDs presents fewer problems in determining layout and placement

8、 of symbols. We conclude, therefore, that DFDs are easier to construct than are flowcharts. You might have a different opinion.DQ4-3Describe the who, what, where, and how of the following scenario. A customer gives his purchase to a sales clerk, who enters the sale in a cash register and puts the mo

9、ney in the register drawer. At the end of the day, the sales clerk gives the cash and the register tape to the cashier.ANS.Who =The sales clerk performs the data processing activities. The customer and the cashier are entities in the relevant environment.What =(1)Give purchase to sales clerk(2)Enter

10、 sale in register (if it is an electronic register, data stores could be updated)(3)Put money in drawer(4) Give cash and register tape to cashier.Where =Store.How =A manual process is performed by the sales clerk using a cash register.DQ4-4 Why are there many correct logical DFD solutions? Why is th

11、ere only one correct physical DFD solution?ANS.For each sensible grouping of logical activities, there is a correct logical DFD. And, since there are often many sensible groupings, there are multiple correct solutions. However, there is only one correct physical DFD for each system, because these di

12、agrams are constructed directly from a description of the system. There is a one-to-0ne correspondence between entities and bubbles, leaving little or no room for interpretation.DQ4-5 Explain why a flow from a higher- to a lower-numbered bubble on a logical DFD is a physical manifestation of the sys

13、tem. Give an example.ANS.If we feel that we must send a data flow from one bubble on a logical DFD to a bubble on that diagram with a lower number, then we must have a picture in our mind of that lower-numbered bubble as a person, place, or thing rather than a logical activity. If you have such a pi

14、cture, your diagram will represent a physical description of the system, regardless of the labels that we might assign to the flows and to the bubbles. Let's use Figure 4.11 for an example. If in that DFD we sent the data flow "Cash receipts total" to bubble number 2.0, we would have a

15、 physical data flow. Perhaps we included such a flow because we picture bubble 2.0 as a place rather than as a function. That would be a mistake in constructing a logical DFD.DQ4-6Compare and contrast the purpose of and techniques used in drawing physical DFDs and logical DFDs.ANS.We draw physical D

16、FDs to depict a system's entitiesboth internal and externaland to characterize the communications between those entities. We draw logical DFDs to describe the functionsor information processing activitiesperformed by the system.We use the same symbols for drawing logical and physical DFDs. Howev

17、er, the way we use those symbols differs. In a physical DFD, the bubbles are labeled with the names of entities, while in a logical DFD, the labels describe the functions being performed. In a physical DFD the labels on the data flows and on the data stores are actual specific names that describe th

18、e method used for communicating and for storing the data, while in a logical DFD, those labels are generic descriptions or names that describe the data.DQ4-7 "If we document a system with a system flowchart and data flow diagrams, we have over-documented the system." Discuss.ANS.We don'

19、;t agree with this statement. Each tool documents a different aspect of a system and is used for a different purposeA systems flowchart depicts a system's information and operations activities and superimposes those activities onto the organization's structure. We use the flowchart to unders

20、tand the system's activitiesboth information and operationsand to analyze the system's controls.Data flow diagrams concentrate on the data, the entities that act on the data, and the information systems functions being performed by a system. We use the DFDs to analyze each of these elements

21、of a system. Also, we use the logical DFD extensively in the development of new systems.DQ4-8 "Preparing a table of entities and activities as the first step in documenting systems seems to be unnecessary and unduly cumbersome. It would be a lot easier to bypass this step and get right to the n

22、ecessary business of actually drawing the diagrams." Do you agree? Discuss fully.ANS.We don't agree. With practice, preparation of a table of entities and activities is not difficult. Also, we find that we prefer to prepare this table before drawing any diagrams because the table helps us t

23、o lay out the diagrams and to avoid mistakes and minimize the need for redrawing.DQ4-9 "In terms of the sequence used in documenting systems, it would be easier to prepare a systems flowchart before we prepare data flow diagrams." Do you agree? Discuss fully.ANS.We don't agree. Those o

24、f you familiar with flowchartsand not familiar with DFDsmight prefer to start with a flowchart. However, our experience is that a flowchart is the most difficult of the diagrams to draw because: the flowchart uses many more symbols than the other diagrams, must be carefully laid out, and may require

25、 complicated on- and off-page connectors. After completing the table of entities and activities and the DFDs, we have found that completing a systems flowchart is relatively uncomplicated.DQ4-10"Since there are computer-based documentation products that can draw data flow diagrams and systems f

26、lowcharts, learning to draw them manually is a waste of time." Do you agree? Discuss fully.ANS.We disagree, partly. We have used computer-based documentation packages and believe that you must know something about drawing DFDs and flowcharts before you can use such packages effectively. However

27、, you might develop your documenting skills by using such a package rather than by practicing manual diagram preparation. The faculty in our English department believes that students can be better writers, if they learn to write using a word-processing package. Perhaps students would prepare better

28、documentation if they were to learn to prepare DFDs and flowcharts while using a documentation package.ProblemsNOTE TO INSTRUCTORS: Additional problems can be created from the diagrams and solutions for Problems 4-1 through 4-3. First, you could provide the students with the narrative and a partiall

29、y completed diagram requiring that the students fill in the missing parts of the diagram. Or, you could provide the diagram and a partially completed narrative and require that the students fill in the blanks in the narrative.P4-1 ANS.At the Companys sales office, sales representatives answer custom

30、er calls and enter customer orders into the computer. The computer accesses the Inventory master data (on disk) to determine the availability and prices for the items requested. Also, the computer accesses the Customer master data (on disk) to determine the customers credit limit and compares that l

31、imit to the balance outstanding on the Accounts receivable master data (on disk) and to the amount of the order.Next, the computer updates the inventory master data and notifies the clerk that the order has been accepted. The clerk notifies the customer by phone. Also, the computer prints a two-part

32、 picking ticket on a printer located in the warehouse. In the warehouse, clerks annotate the picking ticket (we assume that it is annotated with the quantities picked), file copy 2 in the warehouse and send copy 1 to shipping (we assume that it is sent along with the goods).In shipping, clerks prepa

33、re a two-part packing slip, file copy 2 with the annotated picking ticket and give copy 1 to the carrier (we assume that the packing slip is attached to the goods).P4-2 ANS.Potential customers contact this company with a request for services. A contract is prepared and filed in the Contract file and

34、 a copy of the contract is given to the customer.Using a Report of hours worked received from the Operations office, the hours worked are recorded into the Hours worked file.Periodically, monthly statements are prepared using data from the Contract file and the Hours worked file. Monthly statements

35、are sent to the customers and amounts due are recorded in the Accounts receivable master data. At the same time, a Contracts not billed report is prepared and sent to the Central sales office.P4-3 ANS.As orders are received at the Central sales office, the sales clerk enters the orders into the comp

36、uter. The computer reviews the order, checks the customers credit (by comparing the credit limit in the Customer master data to the amount of the order plus the balance outstanding on the Accounts receivable master data and the orders outstanding on the Sales order master data) and logs the order on

37、 the System log.Once the computer has notified the sales clerk that the order has been accepted, the clerk records the order on the Clerks log (a manual log book). At the same time, the computer checks for available inventory on the Inventory master data disk and prints a packing slip on a printer l

38、ocated at one of the companies regional warehouses. As the packing slip is printed, the order is recorded on the Sales order master data disk.As orders are filled at the regional warehouses, a Filled order document is sent to the warehouse supervisor who then enters the order (order number and quant

39、ities shipped) into the computer. The computer records the shipment by updating the Inventory master data, the Sales order master data and writing the Sales journal. The supervisor then files the filled orders (by order number).At the end of each day, the computer prints a log of the events entered

40、that day by reading them from the systems log. The log is sent to the central sales office, where clerks compare it to the one that they have kept throughout the day.Problems 4 through 7Lincoln Company SolutionsP4-4a. Table of entities and activities for LincolnEntitiesParaActivitiesCustomer21. Pres

41、ent items, cash, LCCSales ClerksComputerSales Clerks223322. Prepare LCC Charge Sales Slips3. Key sales into cash register4. Capture sales event data5. Store sales event data on a disk (the Sales Event Data) 6. Forward LCC Charge Sales Slips to Store CashierStore Cashier227. Batch LCC Charge Sales Sl

42、ips8. Send LCC Charge Sales Slips to Cash Receipts Section in BostonComputerCash Receipts33339. Print a Sales Report10. Send Sales Report to Cash Receipts Section 11. Reconcile LCC Charge Sales Slips to Sales Report12. Send LCC Charge Sales Slips to Data Processing (Data Preparation)Data Preparation

43、 Clerks3313. Scan LCC charges to record charges on the Credit Sales Data14. Send Credit Sales Data to Computer Room Computer33315. Record AR Master Data (with Credit Sales Data)16. Prepare Customer Statements17. Send Statements to the Customers Figure SM-4.1Problem 4 part b solutioncontext diagramfo

44、r Lincoln CompanyFigure SM-4.2Problem 5 solutionphysical DFDfor Lincoln CompanyP4-6a. Annotated table of entities and activities for Lincoln CompanyEntitiesParaActivitiesProcessSales Clerks22. Prepare LCC Charge Sales Slips23. Key sales into cash registerComputer24. Capture sales event data1.0 Captu

45、re sales25. Store sales event data on a disk (the Sales Event Data)Store Cashier27. Batch LCC Charge Sales SlipsComputer39. Print a Sales Report2.0 Reconcile Customer ChargesCash Receipts3 11. Reconcile LCC Charge Sales Slips to Sales ReportData PreparationClerks313. Scan LCC Charges to record charg

46、es on the credit sales data3.0 Record SalesComputer3 15. Record AR Master data (with Credit Sales data)Computer3 16. Prepare Customer Statements4.0 Prepare StatementsFigure SM-4.3Problem 6 part b solutionlogical DFDfor Lincoln CompanyAccounting Information Systems, 6e 4-9Figure SM-4.4Problem 7 solut

47、ionsystems flowchartfor Lincoln CompanyBono Insurance SolutionsP4-4a. Table of entities and activities for Bono InsuranceEntitiesParaActivitiesCustomer1 1.Send request for auto insuranceSales office (sales clerks)Data preparation section (data entry clerks)Computer operations (computer)Sales office

48、(sales clerks)Computer operations (computer)Sales office (sales clerks)111112222222222233332. Prepare policy request forms3. File policy request form 4.Forward completed policy request forms to input preparation section5.Key policy request forms6.Key-verify policy request forms to policy events data

49、 7. Retrieve policy event data from the network8Edit policy event data9.Sort policy event data10. Delete erroneous events from policy event data11.Print erroneous events on error report12. Send error report to sales office13. Review error report14.Correct errors15 Contact customer, if necessary16.Pr

50、epare another policy request form (to replace erroneous form)17.Submit new policy request form with other forms to data preparation18.Print a summary report listing good events19.Send summary report to sales office20.Compare summary report to file copy of policy request form21.Notify computer operations to go ahead with processing (If everything checks out)Computer operations (computer)333322.When notified, process policy event d