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Systems Analysis and Design, Ninth Edition
Page 1 of 48
Systems Analysis and Design Ninth Edition
End of Chapter Solutions CHAPTER FIVE
DATA AND PROCESS MODELING ANSWERS TO CASE-SIM: SCR ASSOCIATES 1. Jesse wants to see a context diagram and a diagram 0 DFD for TIMS. Sample context diagram:
CORP ORA T E
T RA I NI NG
CL I E NT
A DM I NI S T RA T OR
I NS T RUCT OR
T RA I NI NG S CHE DUL E
RE P ORT S T RA I NI NG S UM M A RY
DE CI S I ONS
COURS E RE QUE S T
COM P L E T ION DA T A
0
CONF I RM A T I ON
ROS T E R
S T UDE NT I NV OI CE
COURS E A S S I GNM E NT T IM S SYST EM
P A Y M E NT
COURS E DA T A COURS E S
A CCOUNT I NG DA T A A CCOUNT I NG SYST EM
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Sample diagram 0 DFD: TRAINING REPORTS
TRAINING ADM INISTRATOR
COURSES
STUDENT SCHEDULE DECISIONS
PAYM ENT INVOICE COURSE REQUEST
1
COURSE DATA
M ANAGE COURSE SCHEDULING
COURSE ASSIGNM ENT
2
REGISTER STUDENTS CURRENT SCHEDULE
ACCOUNTING DATA ACCOUNTING SYSTEM
CONFIRM ATION
D2
SCHEDULE DATA SCHEDULE DATA
REGISTRATION DATA
ROSTER 3
INSTRUCTOR
D1
STUDENT DATA M AINTAIN TRAINING RECORDS COM PLETION DATA
STUDENT DATA
4
PRODUCE REPORTS
TRAINING DATA TRAINING DATA
D3
TRAINING DATA TRAINING DATA
CORPORATE CLIENT
TRAINING SUM M ARY
2. Need to review the JAD session summary again! Try to identify four main TIMS functions and draw a lower-level DFD for each process. The four main functions are shown as subprocesses in diagram 0 DFD. They are: MANAGE COURSE SCHEDULING (Process 1), REGISTER STUDENTS (Process 2), MAINTAIN TRAINING RECORDS (Process 3), and PRODUCE REPORTS (Process 4). Examples of the four lower-level DFDs follow:
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Diagram 1 DFD: (External symbols omitted for clarity) D5
D4
INSTRUCTOR DATA
COURSE HIS TORY
INSTRUCTOR DA TA
COURSE HISTORY
SCHE DULE DE CISIONS COURSE DA TA
1.2
1.1
INSTRUCTOR NEEDS ANALYZE SCHE DULE DE MA ND
SCHE DULE DA TA
ANALYZE INSTRUCTOR AV AILAB ILITY
COURSE DA TA TRAINING DA TA
COURSE AS SIGNMENT
1.3
CREA TE SCHE DULE
CURRENT SCHE DULE
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Diagram 2 DFD: (External symbols omitted for clarity) COURSE REQUEST
CONFIRMATION SCHEDULE DATA
REGISTRATION DATA
2.2
2.1
HANDLE INVOICES AND PAYMENTS
PROCESS COURSE REQUESTS
INVOICE
PAYMENT
INVOICE AND PAYMENT DATA
REGISTRATION DATA 2.5
D6
ACCOUNTING DATA STUDENT STATUS
REGISTRATION UPDATE REGISTRATION DATA DATA
INVOICE AND PAYMENT DATA 2.3
COURSE ROSTER DATA
PREPARE ACCOUNTING DATA
2.4
CREATE COURSE ROSTERS
COURSE ROSTER DATA
ACCOUNTING DATA
D7
COURSE ROSTERS
ROSTER
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Diagram 3 DFD: (External symbols omitted for clarity) COMPLETION DATA
TRAINING DATA
3.1
UPDATE TRAINING DATA
TRAINING DATA
TRAINING DATA
D3
TRAINING DATA
TRAINING DATA
3.2
STUDENT DATA
UPDATE STUDENT DATA
STUDENT DATA
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Diagram 4 DFD: (External symbols omitted for clarity) 4.1
TRA INING S UMMA RY DA TA
P RODUCE TRA INING S UMMA RY
TRA INING S UMMA RY
RE P ORT DA TA
D8
RE P ORT DA TA FILE
RE P ORT DA TA
4.2
TRA INING RE P ORT DA TA
P RODUCE TRA INING RE P ORTS
TRA INING RE P ORTS
3. Prepare a reply to Jesse’s message about CASE tools. Search the Internet to find two more alternatives. Answers will vary. The memo asks for two additional CASE tool choices. A search for CASE tools will point to many potential vendors and products. Encourage students to come up with as much information as possible.
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4. Prepare a decision table and a decision tree that show the logical rules described in Jesse’s message about fees and discounts. A sample decision table and a second version with simplified rules follow: RULES Multiple courses? Employed by SCR client? Client service rep waiver? Eligible for discount A Eligible for discount B Not eligible for discounts
1 Y
2 Y
3 Y
4 Y
5 N
6 N
7 N
8 N
Y
Y
N
N
Y
Y
N
N
Y
N
Y
N
Y
N
Y
N
X
X
X
X
X
X
X
X
X
X X
Simplified rules: RULES Multiple courses? Employed by SCR client? Client service rep waiver? Eligible for discount A Eligible for discount B Not eligible for discounts
1 Y
2 Y
3 Y
4 N
5 N
6 N
Y
N
N
Y
N
N
-
Y
N
-
Y
N
X
X
X
X
X
X
X X
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A sample decision tree follows:
Employed by SCR client?
No
Yes
Eligible for discount A and B
Yes Client service rep Yes override?
Eligible for discount A and B
No
Multiple courses
Eligible for discount A
No
Employed by SCR client? Eligible for discount B
Yes
No
Client service rep Yes override?
Eligible for discount B
No Not eligible for discounts
ANSWERS TO CHAPTER EXERCISES Review Questions 1. Describe data and process modeling and name the main data and process modeling techniques. Data and process modeling is a process-centered approach because it focuses on the flow of data and the processes that affect that data. Data and process modeling produces a logical model of a business information system by examining the system’s inputs, outputs, and processes, and by focusing on the flow of data through the system. Because users and managers often think in terms of business processes, they find it easy to relate to a processcentric approach. The three main data and process modeling techniques are DFDs, the data dictionary, and process description tools. Data flow diagrams (DFDs) show the flow of data through an information system in a graphical, top-down fashion. The data dictionary documents the contents of data flows, data stores, external entities, and processes. Process description tools include structured English, decision tables, and decision trees. Structured English is a subset of standard English used to describe logical processes clearly and accurately. A decision table is a tabular description of a logical structure. A decision tree is a horizontal graphic representation of a logical structure. (Pages 198, 200, 217, 224-230)
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2. Describe the Gane and Sarson symbols used for processes, data flows, data stores, and entities. Give four examples of typical names for processes, data flows, data stores, and entities. A process receives input data and changes its content, form, or both. The Gane and Sarson symbol for a process is a rectangle with rounded corners, while the Yourdon symbol is a circle. The name of the process is placed inside the symbol. Examples of good process names are APPLY RENT PAYMENT, CALCULATE COMMISSION, ASSIGN FINAL GRADE, VERIFY ORDER, and FILL ORDER. A data flow is a path by which data moves from one part of an information system to another. A data flow can represent one or more data elements. The symbol for a data flow is a line with an arrowhead, and the name of the data flow is placed above, below, or alongside the line. The line’s arrowhead shows the direction in which the data flows. Examples of good data flow names are DEPOSIT, INVOICE PAYMENT, STUDENT GRADE, ORDER, and COMMISSION. A data store is a data repository. A data store in a DFD represents a location where the system must store data that one or more processes need to access. The Gane and Sarson symbol for a data store is a flat rectangle open on the right side. The Yourdon symbol is two parallel lines. The name of the data store is placed inside the symbol. Typical data store names might include PAYROLL ITEMS, CLASS ROSTER, INVENTORY LIST, and COURSE SCHEDULE. An external entity is a person, department, outside organization, or other information system that provides data to the system or receives output from the system. The symbol for an external entity in both sets is a square. The Gane and Sarson symbol usually is shaded, and the name of the external entity is placed inside the symbol. Some examples of entity names might be CUSTOMER, BANK, VENDOR, or ACCOUNTING SYSTEM. (Pages 200 205) 3. What is the relationship between a context diagram and diagram 0, and which symbol is not used in a context diagram? The context diagram contains only one process symbol, process 0, which represents the entire system. Diagram 0 is a more detailed (or exploded, partitioned, or decomposed) version of process 0 on the context diagram. The major processes, data flows, and data stores for the information system are shown on diagram 0. The data store symbol is not used in a context diagram. Use a data store only when two or more processes use that data store. Otherwise, the data store is internal to a process and not visible from the outside. Because a context diagram involves only one process, all data stores are internal to that process and do not appear in the context diagram. (Pages 207 - 212) 4. What is meant by an exploded DFD? An exploded data flow diagram is a more detailed or expanded version of a higher-level process. (Page 213) 5. Describe a data dictionary and give examples of how and when it is used. A data dictionary is a central storehouse of information about the system’s data. An analyst uses the data dictionary to collect, document, and organize specific facts about the system,
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including the contents of data flows, data stores, entities, and processes. The data dictionary also defines and describes all data elements and meaningful combinations of data elements. During enterprise modeling, the data dictionary documents the contents of data flows, data stores, external entities, and processes that appear in the information system's data flow diagrams. (Page 217) 6. Explain the DFD leveling technique. Leveling also is called exploding, partitioning, or decomposing. Leveling describes the technique of representing the graphical model of an information system first as a single process, and then in greater and greater detail, until all processes are functional primitives. (Pages 212-213) 7. What is a balanced DFD? A balanced data flow diagram is one that has the input and output data flows of the parent process preserved on the child data flow diagram. (Page 214) 8. Describe the steps in creating a decision table. A decision table is a tabular description of a logical structure. The four steps are: a. Place a heading at the top left that names the table. b. Enter the conditions under the heading, with one condition per line, to represent the customer status and availability of products. c. Enter all potential combinations of Y/N (for yes and no) for the conditions. Each column represents a numbered possibility called a rule. d. Place an X in the action entries area for each rule to indicate the outcome of the rule. (Page 226) 9. Discuss the pros and cons of decision tables versus decision trees. Decision trees and decision tables provide the same results, but in different forms. As the chapter points out, a decision tree is a graphical representation of the same conditions, actions, and rules found in a decision table. Decision trees show the logic structure in a horizontal form that resembles a tree with the roots at the left and the branches to the right. Like flowcharts, decision trees are useful ways to present the system to management. In many situations, a graphic is the most effective means of communication. Like a decision table, a decision tree illustrates the action to be taken based on certain conditions, but presents it graphically. Whether to use a decision table or a decision tree often is a matter of personal preference. A decision table might be a better way to handle complex combinations of conditions. On the other hand, a decision tree is an effective way to describe a relatively simple process. (Pages 226 - 230) 10. What is structured English? Structured English is a subset of standard English used to describe logical processes clearly and accurately. (Page 225)
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Discussion Topics 1. Suppose you were assigned to develop a logical model of the registration system at a school or college. Would you be better off to use a top-down approach, or would a bottomup strategy be better? What would influence your decision? The textbook points out that most analysts use a top-down model. They create the context diagram, then diagram 0, then all the child diagrams for diagram 0, and so on. Other analysts follow an alternative bottom-up strategy. With a bottom-up strategy, you first identify all functional primitives, data stores, external entities, and data flows. Then group processes with other related symbols to develop the lowest-level diagrams. Next, group those diagrams in a logical way to form the next higher level. Work up until you reach diagram 0. There is no single answer to this question. Regardless of which strategy used, apply the suggestions and guidelines discussed in this chapter. The main objective is to ensure that your model is accurate and easy to understand. 2. Some systems analysts find it better to start with a decision table, then construct a decision tree. Others believe it is easier to do it in the reverse order. Which do you prefer? Why? By now, students should see pros and cons both ways. They should realize that the answer might depend on the audience and the complexity of the process description. Divide the group into teams, and ask them to present the best arguments in a debate format. 3. A systems analyst attended a week-long workshop on structured analysis. When she returned to her job, she told her boss that structured analysis was not worth the time to learn and use on the job. Her view was that it was too academic and had too much new terminology to be useful in a practical setting. Do you agree or disagree? Defend your position. Students typically support both positions. There are some arguments for agreeing with the systems analyst's viewpoint. First, if the organization already has a systems analysis methodology that works effectively, there is no reason to introduce a new approach. Second, just because some people find structured analysis to be useful does not mean that the organization will find it to be useful. Third, learning and adopting any new method involves time and cost, which need to be identified and allocated. Fourth, before the introduction of structured analysis, other systems analysis methodologies were used, so there probably will be other new approaches in the future to replace structured analysis. Some arguments for disagreeing with the systems analyst's viewpoint follow. First, many companies use structured analysis and many experts endorse this approach, so structured analysis must be an effective approach. Second, if the company currently does not have a standard systems analysis methodology, structured analysis is as good as any methodology, and a standard approach would be beneficial to the company. Third, learning something new is good, even if the company only ends up questioning what they currently do and how they do it.
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Fourth, the company must keep up-to-date in order to handle Web-based research, understand technology developments, and communicate effectively with other IT professionals. 4. This chapter describes a black box concept that allows more detail to be shown as a process is exploded. Can the concept be applied in business management generally, or is it limited to information systems design? Provide reasons and examples with your answer. Modular design concepts can be applied in any situation. Students should understand that a modular approach simply breaks tasks or processes down into smaller units that easily can be rearranged, reassigned, and managed. In Chapter 3, students learned about project management, and they can see how tasks are broken down into basic units that can be measured and tracked. A familiar example of modular design might be prefabricated roof trusses that can be lifted into place and tied into a home construction system. Similarly, an auto manufacturer might use the same ignition module for several models. A child playing with a Legos set is an excellent example of flexible modular design at work. Projects 1. Draw a context diagram and a diagram 0 DFD that represents the registration system at your school or an imaginary school. The DFDs were created with Visible Analyst CASE tool. The context diagram is very basic and does not include other entities that might be added, including Instructor, Registrar, and Classroom. The context diagram follows:
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The diagram 0 DFD follows:
2. On the Internet, locate at least three firms that offer CASE tools. Write e-mail messages to the companies to find out whether they offer demonstration copies or student versions of their products. Figure TK 2-3 in Part B of the Systems Analyst’s Toolkit lists many CASE tool vendors. Students might be able to visit vendor Web sites to determine whether demonstration copies or student versions are available. In most cases, however, companies respond promptly to e-mail requests for product information. 3. Suppose that you want to demonstrate a decision table to someone who has never seen one. Think of an example, with two or three conditions, from everyday life. Draw a decision table that captures all possible outcomes. Students should be able to suggest many situations where several conditions control the outcome. Some suggestions might be course prerequisites (and possible waivers) that determine whether a student can take a particular course; various discounts that can (or cannot) be combined to change the price at a retail store; or a company policy that allows an employee to take sick leave if he or she has enough seniority and accumulated sick leave time.
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4. The data flow symbols shown on page 201 were designed by Ed Yourdon, a well-known IT author, lecturer, and consultant. Many IT professionals consider him to be among the most influential men and women in the software field. Learn more about Mr. Yourdon by visiting his Web site at www.yourdon.com, and write a brief review of his accomplishments. This is an excellent opportunity for students to learn more about one of the leading figures in the IT world. Mr. Yourdon has been extremely influential and has made an enormous contribution to IT modeling and systems design concepts. ANSWERS TO APPLY YOUR KNOWLEDGE 1
Digital Consulting Situation: You are a senior systems analyst at Digital Consulting, a growing IT consulting firm. You are leading the development team for a major client. You need to explain structured analysis to your two newly hired junior analysts (Sara and Mike) before meeting with the client tomorrow afternoon. 1. Describe the rules for creating a context diagram. a. Start by placing a single process symbol in the center of the page. The symbol represents the entire information system, and you identify it as process 0. b. Next, place the external entities around the perimeter of the page, and use data flows to connect the entities to the central process. c. Do not show any data stores in a context diagram because data stores are internal to the system. d. Place the external entities around the central process and label them. e. Create labeled input and output data flows between the external entities and the central system. 2. Make a basic list of dos and don’ts when developing DFDs. The basic rules, or conventions that apply to DFD development are: a. Each context diagram must fit on one page. b. The process name in the context diagram should be the name of the information system. c. Use unique names within each set of symbols. d. Do not cross lines. e. Use a unique reference number for each process symbol. In addition to these rules, the systems analyst must use the proper DFD shapes, connect them correctly, and produce a leveled, balanced set of DFDs. 3. Explain the importance of leveling and balancing. When lower-level diagrams, also called child diagrams, are needed to show detail, it is essential that they be leveled and balanced. Leveling is the process of drawing a series of increasingly detailed diagrams, until the desired degree of detail is reached. Balancing maintains consistency among the entire series of diagrams, including input and output data flows, data definition, and process descriptions. Leveling displays the information system as a single process and then shows more
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detail until all processes are functional primitives. At that point, analysts describe the set of DFDs as leveled. Leveling also is called exploding, partitioning, or decomposing. Because analysts create DFDs as a series of top-down pictures of an information system, each lower level provides additional details. DFDs must be balanced properly. A balanced set of DFDs preserves the input and output data flows of the parent on the child DFD. Figure 5-19 on page 215 shows a balanced DFD; it has the same input and output flows as its parent, which is process 1, FILL ORDER. 4. Ask Sara and Mike to review the order system context diagram on page 208, and compare it to the order system diagram 0 DFD on page 212. Then ask them to answer the following questions: (a) How many external entities are shown in each diagram? (b) In each diagram, how many data flows connect to the external entities? (c) How many subprocesses are identified in the diagram 0 DFD? (d) Could the data store have been shown in the context diagram? Why or why not? (a) There are five entities in each diagram. (b) Nine data flows connect to the external entities in each diagram. (c) Three sub-processes are identified in diagram 0 DFD. (d) The data store could not have been shown in the context diagram because a data store cannot connect to an external entity. The data store can connect to one or more processes, and it is shown in the diagram 0 DFD.
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Precision Tools Situation: Precision Tools sells a line of high-quality woodworking tools. When customers place orders on the company’s Web site, the system checks to see if the items are in stock, issues a status message to the customer, and generates a shipping order to the warehouse, which fills the order. When the order is shipped, the customer is billed. The system also produces various reports. 1. Draw a context diagram for the order system. A sample context diagram might look like this: IN-STOCK REQUE ST
ORDER
WAREHOUSE
CUS TOMER P AY ME NT 0
S TATUS MES SA GE
S HIP PING ORDE R ORDER S YS TEM
S HIP PING CONFIRMATION
INVOICE INVE NTORY REP ORTS
ACCOUNTING DEP ARTME NT
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2. Draw a diagram 0 DFD for the order system. A sample diagram 0 might look like this: SHIPP ING CONFIRMATION 1
IN-STOCK RE QUES T
ORDE R CHECK STATUS
CUSTOMER
STATUS DA TA
STATUS ME SS AGE
WARE HOUS E
ORDE R DATA
D1
PE NDING ORDE RS
2
INVOICE
ORDE R DA TA
PA YMENT IS SUE ME SS AGES 5
3
MA NA GE ACCOUNTS RE CE IVA BLE
GE NE RA TE SHIPP ING ORDE R
ACCOUNTING DA TA D3
SHIPP ING ORDE R
ACCOUNTS RE CE IVA BLE DA TA ACCOUNTS RE CE IVA BLE DATA 4
ORDE R DATA PRODUCE RE PORTS
INVENTORY RE PORTS
ACCOUNTING DE PA RTMENT
3. Name four attributes that you can use to define a process in the order system. Typical attributes used to define processes are: Process name or label: The process name as it appears on the DFDs. Purpose or description: A brief statement of the process’s general purpose. Process number: A reference number that identifies the process and indicates relationships among various levels in the system. Input data flows: The standard DFD names for the data flows entering the process. Output data flows: The standard DFD names for the data flows leaving the process.
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Process description: This section is filled in only if the process is a functional primitive. For functional primitives the process description documents the processing steps and business logic.
4. Name four attributes that you can use to define an entity in the order system. Typical attributes used to define entities are: External entity name: The external entity name as it appears on the DFDs. Alternate name(s): Any aliases for the external entity name. Description: Describe the external entity and its purpose. Input data flow: The standard DFD names for the input data flows to the external entity. Output data flows: The standard DFD names for the data flows leaving the external entity. 3
Claremont School Situation: The Claremont School course catalog reads as follows: “To enroll in CIS 288, which is an advanced course, a student must complete two prerequisites — CIS 110 and CIS 286. A student who completes either one of these prerequisites and obtains the instructor’s permission, however, will be allowed to take CIS 288.” 1. Create a decision table that describes the Claremont School course catalog regarding eligibility for CIS 288. Show all possible rules. Remind students to follow the four steps outlined next to Figure 5-35 on page 226. The initial version of the decision table, which contains all possible rules, should look something like the following: RULES CIS 110 CIS 286 WAIVER ELIGIBLE INELIGIBLE
1 Y Y Y X
2 Y Y N X
3 Y N Y X
4 Y N N
5 N Y Y X
X
6 N Y N
7 N N Y
8 N N N
X
X
X
2. Simplify the table you just created. Describe the results. In this example, Rules 1 and 2 can be combined, because if both conditions are met, a waiver is not needed and is irrelevant. Also, Rules 7 and 8 can be combined, because if neither condition is met, a waiver cannot be used. Therefore, after simplification, six rules remain, as shown: RULES CIS 110 CIS 286 WAIVER ELIGIBLE INELIGIBLE
1 Y Y X
2 N Y Y X
3 N Y N X
4 Y N Y X
5 Y N N
6 N N -
X
X
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3. Draw a simplified decision tree to represent the Claremont School catalog. Describe the results. The decision tree uses the same logic as the table above. Where the waiver is not relevant, it is not shown. Therefore, the eight rules can be simplified to six rules, and the tree should look like this: Eligible CIS 286 No CIS 286 CIS 110
Waiver No Waiver
Eligible
Not Eligible Eligible
Waiver
No CIS 110 CIS 286
No Waiver
Not Eligible
No CIS 286 Not Eligible 4. Why might you use a decision tree rather than a decision table? Decision trees are effective ways to present the system to management. Decision trees and decision tables are considered equivalent, but in different forms — a graphic versus a table. Whether to use a decision table or a decision tree often is a matter of personal preference. A decision table might be a better way to handle complex combinations of conditions. On the other hand, a decision tree is an effective way to describe a relatively simple process.
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4 City Bus Lines Situation: City Bus Lines is developing an information system that will monitor passenger traffic, peak travel hours, and equipment requirements. The IT manager wants you to document a process called BALANCE that determines whether extra buses currently are needed on a particular route. The BALANCE process automatically assigns additional buses to that route, but only if all other routes are operating on schedule. In any case, a supervisor can override the automatic BALANCE process if he or she so desires. 1. Create a decision table that describes the bus transfer process. A sample decision table follows: RULES Extra buses needed? All other routes on schedule? Supervisor override? Assign extra buses Do not assign extra buses
1 Y
2 Y
3 Y
4 Y
5 N
6 N
7 N
8 N
Y
Y
N
N
Y
Y
N
N
Y
N
Y
N
Y
N
Y
N
X
X
X X
X
X
X
X
After simplification the table might look like this: RULES Extra buses needed? All other routes on schedule? Supervisor override? Assign extra buses Do not assign extra buses
1 Y
2 Y
3 Y
4 N
Y
N
N
-
-
Y
N
-
X
X X
X
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2. Draw a decision tree that describes the bus transfer process. The decision tree should look something like the following:
Other routes on time?
Yes
No Yes
Buses needed?
Assign extra buses Yes
Assign extra buses
No
No extra buses
Dispatcher override?
No No extra buses
3. Name four attributes that you can use to define a data flow in the bus information system. Typical attributes used to define data flows are: Data flow name or label: The data flow name as it appears on the DFDs. Alternate name(s): Aliases for the DFD data flow name(s). Description: Describes the data flow and its purpose. Origin: The DFD beginning, or source, for the data flow; the origin can be a process, a data store, or an external entity. Destination: The DFD ending point(s) for the data flow; the destination can be a process, a data store, or an external entity. Record: Each data flow represents a group of related data elements called a record or data structure. In most data dictionaries, records are defined separately from the data flows and data stores. When records are defined, more than one data flow or data store can use the same record, if necessary. Volume and frequency: Describes the expected number of occurrences for the data flow per unit of time. 4. Name four attributes that you can use to define a data store in the bus information system. Typical attributes used to define data stores are: Data store name or label: The data store name as it appears on the DFDs. Alternate name(s): Aliases for the DFD data store name. Description: Describes the data store and its purpose. Input data flows: The standard DFD names for the data flows entering the data store. Output data flows: The standard DFD names for the data flows leaving the data store. Record: The record name in the data dictionary for the data store. Volume and frequency: Describes the estimated number of records stored in the data store; specifies any growth and change statistics for the data store
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ANSWERS TO CASE STUDIES New Century Health Clinic 1. Prepare a context diagram for New Century’s information system. A sample diagram might look like this:
INS URA NCE P A Y ME NT
CLA IM
P A TIE NT RE P ORTS A ND OUTP UTS
P A TIE NT P A Y ME NT 0 P A TIE NT INP UTS
NE W CE NTURY OFFICE S Y S TE M
OFFICE S TA FF RE P ORTS A ND OUTP UTS OFFICE S TA FF
A ME RICA N ME DICA L A S S OCIA TION
INS URA NCE COMP A NY
P A TIE NT
CP T CODE S
P ROV IDE R RE P ORTS A ND OUTP UTS
P ROV IDE R INP UTS P ROV IDE R
Context diagram for New Century Health Clinic Office System
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2. Prepare a diagram 0 DFD for New Century. Be sure to show numbered processes for handling appointment processing, payment and insurance processing, report processing, and records maintenance. Also, prepare lower-level DFDs for each numbered process. DFDs follow: MTD PAYMENTS MTD PAYMENTS
PATIENT PAYMENT 2
INSURANCE PAYMENT
D4
STATEMENT PROCESS PAYMENT
INSURANCE COMPANY
PATIENT
APPOINTMENT REQUEST
PAYMENT DATA
CLAIM AMERICAN MEDICAL ASSOCIATION
CPT CODES
APPOINTMENT DATA
D6
APPOINTMENT DATA
CHARGES PROVIDER DATA
HOUSEHOLD UPDATE
SERVICE CHARGE D3
PROVIDERS
FEE AND SERVICE DATA
SERVICE DATA
PROVIDER UPDATE
D21
SERVICE DATA D7
HOUSEHOLDS
D5
PROVIDER CHARGES
APPOINTMENT DATA D1
PENDING INSURANCE CLAIMS
D22
HOUSEHOLD DATA 1
PROCESS APPOINTMENT SERVICE DATA
YTD PAYMENTS
PAYMENT UPDATE INSURANCE CLAIM DATA
MTD PAYMENTS
INSURANCE CARRIERS
INSURANCE CARRIER DATA INSURANCE UPDATE
MTD CHARGES
SERVICE CHARGE INSURANCE COMPANY
PATIENT DATA D2
PATIENTS
REPORT
3
PRODUCE REPORTS
CLAIM STATUS SUMMARY APPOINTMENT LIST PATIENT UPDATE
MAILING LABELS
CALL LIST
PROVIDER REPORT
PROVIDER CHANGE INSURANCE CHANGE
OFFICE STAFF
PROVIDER
PATIENT
HOUSEHOLD CHANGE PATIENT CHANGE
REMINDER POSTCARD
Diagram 0 DFD
4
MAINTAIN RECORDS
Systems Analysis and Design, Ninth Edition
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The four main processes shown on diagram 0 DFD are PROCESS APPOINTMENT (Process 1), PROCESS PAYMENT (Process 2), PRODUCE REPORTS (Process 3), and MAINTAIN RECORDS (Process 4). Samples of lower-level diagrams for these four processes follow:
1.3
PATIENT
MODIFY CPT CODE
APPOINTMENT REQUEST
CPT CODES
AMERICAN MEDICAL ASSOCIATION
CPT CODES CPT FEE SCHEDULE
1.1
PATIENT DATA
MAKE APPOINTMENT
APPT DATA
FEE DATA
MTD CHARGES
D7
D26
CPT FEE SCHEDULE
D23
1.4
SERVICE DATA
MODIFY CPT FEE
SCHEDULED SERVICE DATA
SERVICE DATA
PATIENTS
D3
PROVIDERS
PROVIDER DATA
1.2
COMPLETED APPT DATA
PROVIDER CHARGES
COMPLETE APPOINTMENT
SERVICE DATA
INSURANCE CLAIM DATA
SERVICE DATA
D28
D2
SCHEDULED APPOINTMENT DATA APPT DATA
D27
PROVIDER
SERVICE CHARGE
APPT DATA D25
FEE DATA
PENDING D22 INSURANCE CLAIMS
CLAIM
COMPLETED SERVICE DATA INSURANCE CARRIER DATA
D21
CHARGES
D5
INSURANCE CARRIERS
HOUSEHOLD DATA
HOUSEHOLDS
. Diagram 1 DFD
INSURANCE COMPANY
Systems Analysis and Design, Ninth Edition
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PATIE NT PAYMENT 2.1
MTD P AYMENTS
YTD P AYMENTS
PROCESS PATIE NT PAYMENT MTD P AYMENTS
D4
D5
HOUS EHOLDS
2.2 MTD P AYMENTS PAYMENT DATA
PROCESS INSURANCE PAYMENT
PAYMENT UPDA TE D22
PENDING INSURANCE CLAIMS
YTD P AYMENTS
INSURANCE PAYMENT
Diagram 2 DFD
INSURANCE COMP ANY
Systems Analysis and Design, Ninth Edition
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OFFICE STAFF MAILING LABELS
SERVICE DATA CALL LIST
D1
SERVICE DATA SERVICE DATA
APPOINTMENT DATA
D6
MTD PAYMENTS
APPOINTMENT DATA
APPOINTMENT DATA 3.1
3.2
PRODUCE DAILY REPORTS
PRODUCE OTHER REPORTS
SERVICE CHARGE
APPOINTMENT LIST
PROVIDER REPORT PROVIDER
INSURANCE COMPANY REPORT CLAIM STATUS SUMMARY
Diagram 3 DFD
REMINDER POSTCARD STATEMENT
PATIENT
Systems Analysis and Design, Ninth Edition
D6
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APPOINTMENT DATA
D1
SERVICE DATA
CALL LIST DATA
3.1.1
PROVIDER APPOINTMENT DATA
CREATE CALL LIST CALL LIST
3.1.2
OFFICE STAFF
CREATE APPOINTMENT LIST
SERVICE DATA APPOINTMENT LIST
Diagram 3.1 DFD
PROVIDER
Systems Analysis and Design, Ninth Edition
PROVIDER REPORT
APPOINTMENT DATA
3.2.1
SERVICE DATA
CREATE PROVIDER REPORTS
PROVIDER CLAIM STATUS SUMMARY
3.2.3 CREATE MAILING LABELS
STATEMENT DATA
INSURANCE COMPANY REPORT
SERVICE CHARGE
MTD PAYMENTS
PATIENT DATA
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MAILING LABELS OFFICE STAFF
3.2.4 STATEMENT CREATE STATEMENTS
APPOINTMENT DATA
PATIENT
3.2.2 REMINDER POSTCARD CREATE REMINDER POSTCARDS
Diagram 3.2 DFD
Systems Analysis and Design, Ninth Edition
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INSURANCE CHANGE
PATIENT CHANGE
PATIENT
HOUSEHOLD CHANGE 4.1
4.2
4.3
MODIFY PATIENT
MODIFY HOUSEHOLD
MODIFY INSURANCE CARRIERS
PATIENT UPDATE
D2
INSURANCE UPDATE
HOUSEHOLD UPDATE
PATIENTS
HOUSEHOLDS
D5
PROVIDER CHANGE PROVIDER
4.4
D21
INSURANCE CARRIERS
D3
PROVIDERS
PROVIDER UPDATE
MODIFY PROVIDER
Diagram 4 DFD 3. Prepare a list of data stores and data flows needed for the system. Under each data store, list the data elements required. The data flows are as follows: APPOINTMENT DATA APPOINTMENT LIST APPOINTMENT REQUEST APPT DATA CALL LIST CALL LIST DATA CHARGES CLAIM CLAIM STATUS SUMMARY CPT CODES
Systems Analysis and Design, Ninth Edition CPT FEE SCHEDULE FEE AND SERVICE DATA FEE DATA HOUSEHOLD CHANGE HOUSEHOLD DATA HOUSEHOLD UPDATE INSURANCE CARRIER DATA INSURANCE CHANGE INSURANCE CLAIM DATA INSURANCE COMPANY REPORT INSURANCE PAYMENT INSURANCE UPDATE MAILING LABEL DATA MAILING LABELS MTD PAYMENTS OFFICE STAFF REPORTS AND OUTPUTS PATIENT CHANGE PATIENT DATA PATIENT INPUTS PATIENT PAYMENT PATIENT REPORTS AND OUTPUTS PATIENT UPDATE PROVIDER APPOINTMENT DATA PROVIDER CHANGE PROVIDER CHARGES PROVIDER DATA PROVIDER INPUTS PROVIDER REPORT PROVIDER REPORT DATA PROVIDER REPORTS AND OUTPUTS PROVIDER UPDATE REMINDER POSTCARD REMINDER POSTCARD DATA SCHEDULED APPT DATA SCHEDULED SERVICE DATA SERVICE CHARGE SERVICE DATA STATEMENT STATEMENT DATA YTD PAYMENTS The data stores are as follows: COMPLETED APPT DATA COMPLETED SERVICE DATA CPT FEE SCHEDULE HOUSEHOLDS
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Systems Analysis and Design, Ninth Edition INSURANCE CARRIERS MTD CHARGES MTD PAYMENTS PATIENTS PENDING INSURANCE CLAIMS PROVIDERS SCHEDULED APPOINTMENT DATA SCHEDULED SERVICE DATA The data elements for each data store are as follows: COMPLETED APPT DATA (D27) Data elements: APPOINTMENT NUMBER APPOINTMENT DATE START TIME END TIME PATIENT NUMBER PROVIDER NUMBER COMPLETED SERVICE DATA (D28) Data elements: APPOINTMENT NUMBER CPT CODE FEE CPT FEE SCHEDULE (D18) Data elements: CPT CODE CPT FEE PROCEDURE NAME HOUSEHOLDS (D5) Data elements: HOUSEHOLD NUMBER HOUSEHOLD FIRST NAME HOUSEHOLD LAST NAME HOUSEHOLD ADDRESS HOUSEHOLD CITY HOUSEHOLD STATE HOUSEHOLD HOME PHONE HOUSEHOLD WORK PHONE INSURANCE CO. NUMBER EMPLOYER GROUP NUMBER YTD HOUSEHOLD CHARGES YTD HOUSEHOLD PAYMENTS YTD INSURANCE PAYMENTS
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Systems Analysis and Design, Ninth Edition PRIOR BALANCE INSURANCE CARRIERS (D8) Data elements: INSURANCE CO. NUMBER INSURANCE CO. NAME INSURANCE ADDRESS 1 INSURANCE ADDRESS 2 INSURANCE CITY INSURANCE STATE INSURANCE ZIP INSURANCE PHONE MTD CHARGES (D7) Data elements: HOUSEHOLD NUMBER APPOINTMENT NUMBER CPT CODE PROVIDER NUMBER FEE MTD PAYMENTS (D4) Data elements: HOUSEHOLD NUMBER PAYMENT DATE PAYMENT AMOUNT PAYMENT SOURCE INSURANCE CO. NUMBER PATIENTS (D2) Data elements: PATIENT NUMBER PATIENT LAST NAME PATIENT FIRST NAME BIRTHDATE HOUSEHOLD NUMBER RELATIONSHIP CODE LAST EXAM PENDING INSURANCE CLAIMS (D22) Data elements: INSURANCE CO. NUMBER EMPLOYER GROUP NUMBER APPOINTMENT NUMBER CLAIM AMOUNT PAYMENT AMOUNT
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Systems Analysis and Design, Ninth Edition
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PAYMENT DATE INSURANCE CHARGES MTD INSURANCE CHARGES YTD INSURANCE PAYMENTS MTD INSURANCE PAYMENTS YTD INSURANCE BALANCE OUTSTANDING PROVIDERS (D3) Data elements: PROVIDER NUMBER PROVIDER NAME CHARGES MTD CHARGES YTD SCHEDULED APPT DATA (D25) Data elements: APPOINTMENT NUMBER APPOINTMENT DATE START TIME END TIME PATIENT NUMBER PROVIDER NUMBER SCHEDULED SERVICE DATA (D26) Data elements: APPOINTMENT NUMBER CPT CODE FEE 4. Prepare a data dictionary entry and process description for one of the system’s functional primitives. Answers will vary, because students will be using the data flow diagrams they created in responding to previous questions. This assignment can be approached in several ways. Have students use structured English, decision tables, or another documentation technique. Although the New Century processes do not require a complex logical solution, create an additional New Century guideline, or policy, that would require the use of a decision table or decision tree. For example, New Century might decide to send out special reminders for patients in certain age groups or for those who have had certain procedures performed during the past year. The main objective is to provide an opportunity to practice and apply the skills learned in this chapter. Many sample documents have been prepared for several of the functional primitives shown in the DFDs on our data flow diagrams. Use these as examples, and encourage students to develop their own solutions. In addition, a full list of the functional primitives, including input and output data flows, have been provided. SAMPLE DOCUMENTATION FOR PROCESSES 1.1, 1.2, 1.3, AND 1.4:
Systems Analysis and Design, Ninth Edition
PROCESS 1.1: PURPOSE:
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MAKE APPOINTMENT Schedules a patient's appointment and services.
INPUT DATA FLOWS:
APPOINTMENT REQUEST PATIENT DATA CPT FEE SCHEDULE
OUTPUT DATA FLOWS:
SERVICE DATA APPT DATA
PROCESS DESCRIPTION: For each APPOINTMENT REQUEST from PATIENT Retrieve PATIENT NUMBER from PATIENTS Verify PATIENT NUMBER For each CPT CODE in APPOINTMENT REQUEST Retrieve CPT CODE from CPT FEE SCHEDULE Add/Change/Delete CPT CODE in SCHEDULED SERVICE DATA Add/Change/Delete PROVIDER NUMBER in SCHEDULED SERVICE DATA Add/Change/Delete APPOINTMENT NUMBER, APPOINTMENT DATE, START TIME, PATIENT NUMBER in SCHEDULED APPOINTMENT DATA PROCESS 1.2: PURPOSE:
COMPLETE APPOINTMENT Processes an appointment that has been completed
INPUT DATA FLOWS:
EMPLOYER DATA PROVIDER DATA HOUSEHOLD DATA SERVICE DATA APPT DATA
OUTPUT DATA FLOWS:
CLAIM CHARGES PROVIDER CHARGES SERVICE CHARGE SERVICE DATA APPT DATA
PROCESS DESCRIPTION: For each APPOINTMENT NUMBER Retrieve HOUSEHOLD NUMBER from PATIENTS Retrieve EMPLOYER GROUP NUMBER from HOUSEHOLDS Retrieve INS. CO. NUMBER from HOUSEHOLDS For each APPOINTMENT NUMBER in COMPLETED APPOINTMENT DATA Retrieve FEE from SERVICE DATA
Systems Analysis and Design, Ninth Edition
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Apply CHARGE to HOUSEHOLDS Apply PROVIDER CHARGES to PROVIDERS Apply LAST EXAM to PATIENTS Apply FEE to MTD CHARGES Add APPOINTMENT NUMBER, APPOINTMENT DATE, START TIME, END TIME, PATIENT NUMBER in COMPLETED APPOINTMENT DATA Add CPT CODE, PROVIDER NUMBER, FEE in COMPLETED SERVICE DATA Delete APPOINTMENT NUMBER, APPOINTMENT DATE, START TIME, END TIME, PATIENT NUMBER in COMPLETED APPOINTMENT DATA Delete CPT CODE, PROVIDER NUMBER in SCHEDULED SERVICE DATA Send CLAIM to INSURANCE COMPANY PROCESS 1.3: PURPOSE:
INPUT DATA FLOWS: OUTPUT DATA FLOWS:
MODIFY CPT CODE Add/Change/Delete an American Medical Association CPT code CPT CODES CPT CODES
PROCESS DESCRIPTION: For each CPT CODE CHANGE from AMERICAN MEDICAL ASSOCIATION Apply CPT CODE to CPT FEE SCHEDULE PROCESS 1.4: PURPOSE: INPUT DATA FLOWS: OUTPUT DATA FLOWS:
MODIFY CPT FEE Add/Change/Delete a CPT fee FEE DATA FEE DATA
PROCESS DESCRIPTION: For each FEE CHANGE from PROVIDER Apply FEE to CPT FEE SCHEDULE OTHER FUNCTIONAL PRIMITIVE PROCESSES: PROCESS 2.1: PURPOSE: INPUT DATA FLOWS: OUTPUT DATA FLOWS:
PROCESS 2.2:
PROCESS PATIENT PAYMENT Process a payment received from a patient PATIENT PAYMENT MTD PAYMENTS YTD PAYMENTS PROCESS INSURANCE PAYMENT
Systems Analysis and Design, Ninth Edition
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PURPOSE:
Process a payment received from an insurance company
INPUT DATA FLOWS: OUTPUT DATA FLOWS:
INSURANCE PAYMENT MTD PAYMENTS YTD PAYMENTS
PROCESS 3.1.1: PURPOSE:
INPUT DATA FLOWS: OUTPUT DATA FLOWS: PROCESS 3.1.2: PURPOSE:
INPUT DATA FLOWS: OUTPUT DATA FLOWS:
PROCESS 3.2.1: PURPOSE:
INPUT DATA FLOWS:
OUTPUT DATA FLOWS:
PROCESS 3.2.2: PURPOSE:
INPUT DATA FLOWS: OUTPUT DATA FLOWS: PROCESS 3.2.3: PURPOSE:
CREATE CALL LIST Prepare and print the daily call list that shows all patients who are to be called to be reminded of their appointment CALL LIST DATA CALL LIST CREATE APPOINTMENT LIST Prepare and print the daily appointment list that shows all patients and their scheduled services for each provider SERVICE DATA PROVIDER APPOINTMENT DATA APPOINTMENT LIST
CREATE PROVIDER REPORT Prepare and print the weekly provider report that summarizes each provider's charges for the week MTD PAYMENTS PROVIDER REPORT DATA SERVICE CHARGE CLAIM STATUS SUMMARY INSURANCE COMPANY REPORT PROVIDER REPORT CREATE REMINDER POSTCARDS Prepare and print reminder postcards for each appointment REMINDER POSTCARD DATA REMINDER POSTCARD CREATE MAILING LABELS Prepare and print patient mailing labels
INPUT DATA FLOWS:
MAILING LABEL DATA
OUTPUT DATA FLOWS:
MAILING LABELS
Systems Analysis and Design, Ninth Edition
PROCESS 3.2.4: PURPOSE: INPUT DATA FLOWS: OUTPUT DATA FLOWS: PROCESS 4.1: PURPOSE:
INPUT DATA FLOWS: OUTPUT DATA FLOWS: PROCESS 4.2: PURPOSE:
INPUT DATA FLOWS: OUTPUT DATA FLOWS: PROCESS 4.3: PURPOSE:
INPUT DATA FLOWS: OUTPUT DATA FLOWS: PROCESS 4.4: PURPOSE: INPUT DATA FLOWS: OUTPUT DATA FLOWS:
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CREATE STATEMENT Prepare and print monthly statements to patients STATEMENT DATA STATEMENT MODIFY PATIENT Add, change, and delete patient and household data received from patients PATIENT CHANGE PATIENT UPDATE MODIFY HOUSEHOLD Add, change, and delete household data changes received from patients HOUSEHOLD CHANGE HOUSEHOLD UPDATE MODIFY INSURANCE CARRIERS Add, change, and delete insurance carrier data received from patients EMPLOYER CHANGE EMPLOYER UPDATE MODIFY PROVIDER Add, change, and delete provider data PROVIDER CHANGE PROVIDER UPDATE
Systems Analysis and Design, Ninth Edition
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Personal Trainer, Inc. 1. Prepare a context diagram for the new system. Sample context diagram: ACTIVITY DATA
REQUEST ACTIVITY
MEMBER
INVOICE ACTIVITY PAYMENT
CONFIRM ACTIVITY REQUEST
ACCOUNTING REPORTS
0 ASSIGNED ACTIVITY INSTRUCTOR CONFIRM AVAILABILITY
ACCOUNTING RESULTS
PERSONAL TRAINER INFORMATION MANAGEMENT SYSTEM
TREND DATA
TREND REPORTS
MANAGER
SCHEDULE DECISIONS
CHARGE AND PAYMENT DATA
PERSONAL TRAINER ACCOUNTING SYSTEM
2. Prepare a diagram 0 DFD for the new system. Answers will vary. In Chapter 4, students were asked to draw an FDD showing the main operations described in the fact statement. Answers will vary, but the objective is to have students identify three to five functions that will represent major business processes. The sample FDD in Chapter 4 identified four primary functions: MANAGE MEMBERSHIP AND CHARGES INTERFACE WITH ACCOUNTING SYSTEM SCHEDULE COURSES AND ACTIVITIES ANALYZE SALES AND MARKETING TRENDS These four functions can be represented as processes when the context diagram is exploded to diagram 0 DFD.
Systems Analysis and Design, Ninth Edition
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Sample diagram 0 DFD: 1
PAYM ENT
2
ACCOUNTING DATA
M ANAGE M EM BERSHIP AND CHARGES
ACCOUNTING RESUL TS
PERSONAL TRAINER ACCOUNTING CHARGE AND SYSTEM PAYM ENT DAT A
M EM BER DATA
INVOICE M EM BER
INTERFACE WITH ACCOUNTING SYSTEM
4
REQUEST ACTIVITY D2
CONFIRM ACTIVITY REQUEST
M EM BER DATA
ANAL YZE SAL ES AND M ARKETING TRENDS
TREND DATA
TREND REPORTS
3
D1
D3
SCHEDUL E DATA ACTIVITY DATA
CURRENT SCHEDUL E
SCHEDUL E COURSES AND ACTIVITIES
ACCOUNTING REPORTS
M ANAGER
SCHEDUL E DECISIONS ACTIVITY DATA
ACTIVITY DATA
CONFIRM AVAIL ABIL ITY
INSTRUCTOR
ASSIGNED ACTIVITY
ACTIVITY
3. Write a brief memo that explains the importance of leveling a set of DFDs. After reviewing the material starting on page 212, students should describe leveling as the process of drawing a series of increasingly detailed diagrams, until all functional primitives are identified. 4. Write a brief memo that explains the importance of balancing a set of DFDs. Students should be able to describe balancing as a technique that maintains consistency among a set of DFDs by ensuring that input and output data flows align properly.
Systems Analysis and Design, Ninth Edition
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ANSWERS TO CHAPTER CAPSTONE CASE: SOFTWEAR, LIMITED (SWL) Suppose that you are working with Rick and Carla when a new systems request comes in. SWL’s vice president of marketing, Amy Neal, wants to change the catalog mailing program and provide a reward for customers who use the Internet. Amy’s plan specifies that customers will remain on SWL’s mailing list if they either requested a catalog, ordered from SWL in the last two years, or signed the guest register on SWL’s new Web site. To encourage Internet visitors, customers who register on the Web site also will receive a special discount certificate. To document the requirements, Rick wants you to design a decision table. Initially, it appears to have eight rules, but you notice that some of those rules are duplicates, or might not be realistic combinations. 1. Design the decision table with all possibilities. The three separate conditions should produce a total of eight possible rules, and the table should look something like the following example: RULES
1
2
3
4
5
6
7
8
Requested a catalog
Y
Y
Y
Y
N
N
N
N
Ordered in past two years
Y
Y
N
N
Y
Y
N
N
Signed Web site register
Y
N
Y
N
Y
N
Y
N
Remain on mailing list
X
X
X
X
X
X
X
Receive certificate
X
X
X
X
2. Simplify the table by combining rules where appropriate. Now the rules can be simplified by considering the following: a. If a customer registers on the Web site, as in Rules 1, 3, 5, and 7, he or she stays on the mailing list and gets the discount certificate. In this situation, the other two conditions do not really matter. b. If a customer did not register on the Web, then it does matter whether they fulfilled the other conditions. In Rules 2 and 4, the catalog request was present and the 2-year rule does not matter. In Rule 6, the 2-year rule was fulfilled and the catalog request does not matter. c. If none of the conditions is fulfilled, as in Rule 8, the customer is removed from the mailing list and does not receive the discount certificate. The following table shows the simplification just described:
Systems Analysis and Design, Ninth Edition
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RULES
1
2
3
4
5
6
7
8
Requested a catalog
-
Y
-
Y
-
-
-
N
Ordered in past two years
-
-
-
-
-
Y
-
N
Signed Web site register
Y
N
Y
N
Y
N
Y
N
Remain on mailing list
X
X
X
X
X
X
Receive certificate
X
X
X
X
Finally, based on the analysis described in Step 2, the original eight rules can be combined into just four rules, as follows: RULES
1
2
3
4
Requested a catalog
-
Y
-
N
Ordered in past two years
-
-
Y
N
Signed Web site register
Y
N
N
N
Remain on mailing list
X
X
X
Receive certificate
X
3. Draw a decision tree that reflects Amy Neal’s policy. Using the same logic, the decision tree will produce the four rules shown in the final version of the decision table. The layout of the tree will vary depending on which condition is depicted first. The simplest solution is to start with the Web site condition, as follows:
Systems Analysis and Design, Ninth Edition
Remain on mailing list and receive certificate
Signed Web site register Did not sign register
Page 42 of 48
Remain on mailing list
Requested a catalog Did not request a catalog
Ordered in past two years
Remain on mailing list
Did not order in past two years
Remove from mailing list
4. Create a set of structured English statements that accurately describes the policy. Students should review the example in Figure 5-33 on page 225 and use their imagination for this assignment. Explain that the objective is to come up with a reasonable example of structured English — not a detailed process description. A sample solution might look like the following: For each CUSTOMER If REGISTERED ON WEB SITE Else If CATALOG REQUESTED or ORDERED IN 2 YEARS Else Remove from mailing list Remain on mailing list Remain on mailing list and receive certificate
Systems Analysis and Design, Ninth Edition
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Manage the SWL Project You have been asked to manage SWL’s new information system project. One of your most important activities will be to identify project tasks and determine when they will be performed. Before you begin, you should review the SWL case in this chapter. Then list and analyze the tasks, as follows: LIST THE TASKS Start by listing and numbering at least ten tasks that the SWL team needs to perform to fulfill the objectives of this chapter. Your list can include SWL Team Tasks and any other tasks that are described in this chapter. For example, Task 3 might be to Identify the system entities, and Task 6 might be to Draw a context diagram. An answer might include tasks listed in the Chapter Introduction Case, and other examples of tasks found in the SWL case or elsewhere in the chapter. A sample answer follows: Task List Learn how to use data flow diagrams, data dictionaries, and process description tools Learn how to use the four main DFD symbols Understand leveling and balancing concepts Create a data dictionary that will document the DFDs Create a context diagram Create a diagram 0 DFD Create lower-level diagrams Check to assure that all DFDs are leveled and balanced Describe all processes using structured English, decision tables and decision trees Complete a logical data and process model of the system ANALYZE THE TASKS Now study the tasks to determine the order in which they should be performed. First identify all concurrent tasks, which are not dependent on other tasks. In the example shown in Figure 5-47, Tasks 1, 2, 3, 4, and 5 are concurrent tasks, and could begin at the same time if resources were available. Other tasks are called dependent tasks, because they cannot be performed until one or more earlier tasks have been completed. For each dependent task, you must identify specific tasks that need to be completed before this task can begin. For example, you would want to identify the system entities before you could draw a context diagram, so Task 6 cannot begin until Task 3 is completed, as Figure 5-47 shows. Answers will vary. A sample answer follows: Concurrent Tasks 1. Learn how to use data flow diagrams, data dictionaries, and process description tools 2. Learn how to use the four main DFD symbols 3. Understand leveling and balancing concepts
Dependent Tasks 4. Create a data dictionary that will document the DFDs 5. Create a context diagram 6. Create a diagram 0 DFD 7. Create lower-level diagrams
Systems Analysis and Design, Ninth Edition
Page 44 of 48 8. Check to assure that all DFDs are leveled and balanced 9. Describe all processes using structured English, decision tables, and decision trees 10. Complete a logical data and process model of the system
For each dependent task, a sample list of predecessor tasks follows: Dependent Tasks 4. Create a data dictionary that will document the DFDs 5. Create a context diagram 6. Create a diagram 0 DFD 7. Create lower-level diagrams 8. Check to assure that all DFDs are leveled and balanced 9. Describe all processes using structured English, decision tables, and decision trees 10. Complete a logical data and process model of the system
Predecessor Tasks 1,2,3 4 5 6 7 8 9
Chapter 3 describes project management tools, techniques, and software. To learn more, you can visit the Features section on your Student Study Tool CD-ROM, or visit the Management Information Systems CourseMate Web site at www.cengagebrain.com and locate the project management resources library for this book. On the Web, Microsoft offers demo versions, training, and tips for using Project 2010. You also can visit the OpenWorkbench.org site to learn more about this free, open-source software. The Features section on the Student Study Tool CD-ROM includes Web links for Microsoft Project and Open Workbench, and a user guide for Open Workbench. Instructors can demonstrate Microsoft Project if it is available, and show students how to download and install Open Workbench. Instructors also can create additional assignments that use project management software skills in a systems development environment.
Systems Analysis and Design, Ninth Edition
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ANSWERS TO READY FOR A CHALLENGE Instructor Note: Remind students that to view sample answers to Practice Tasks, they can visit the Management Information Systems CourseMate Web site at www.cengagebrain.com, navigate to the resources for this chapter, and locate Ready for a Challenge.
Systems Analysis and Design, Ninth Edition
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Systems Analysis and Design, Ninth Edition
A. Draw a context diagram for the new C3 system that shows the revised design.
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Systems Analysis and Design, Ninth Edition
B. Draw a DFD diagram 0 that shows the revised design.
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