Material Chapter 6 and Part 1 of Chapter 7
A line in a data flow
A data flow
Check
Arrow
Line
Direction of movement
file flowchart
How you want to file
Level 0
Zero one 1.0, 2.0
Inventory Master File
set a parallel lines
Level One Diagram
- As many as necessary Process 1.0 is subdivided into 1.1, 1.2, 1.3 Process 2.0 is subdivided into 2.1, 2.2, 2.3
A data flow
- Pipelines through which packets of information flow - Represented by a directional line - Only one arrow on one end Labeled with noun phrases: desired information, accounts payable data, customer order data (referring to the content)
Design Convection
-Based on what it represents Columns based on areas of responsibility Rough draft of flowchart must be discussed by people involved Clear origin and termination for all documents -Origin: enter the system or created by processes in the system -Termination: filed or cross out of the system boundary Plenty of white space
Design Steps of flowcharts
1)Establish the system boundary. 2)Determine column headings. - Departments, functions, positions 3)List actions performed within each column. - List what each department does 4)Select appropriate symbols. 5)Prepare a first draft .- Keep in mind the design conventions 6)Discuss the draft with others. 7)Revise as needed.
external entity symbol
A DFD related symbol that portrays a source or destination of data outside the system. Person or organization outside the boundary of an information system
Process
A process: transforms incoming data flow to outgoing data flow.• Any set of procedures an organization uses to gather data, change the data into information, or report the information to system users. Two identfying characteristics A number: discuss later A name: verb phrases, like approve, record, calculate or check
A circle in a data flow diagram may be labeled similarly to which shape in a system flowchart
A rectangle
Purchase Order
Arrow
Vendor Invoice
Arrow
Level Two
As many as necessary Process 1.1 is subdivided into 1.1.1,1.1.2 Process 2.3 is subdivided into 2.3.1, 2.3.2, 2.3.3
Level three
As many as necessary Process 1.1.2 is subdivided into 1.1.2.1,1.1.2.2
Which of the following statements about systems flowcharts and data flow diagrams is most true?
Both lines are used in both, but they represent different things and circles are used in both, but they represent different things
teminator
Can be used for a starting and/or ending point
Generic Process Framework
Can be used for any process in a flowchart. Should always be symbolized with a verb phrase such as receive application
Purchase Inventory
Circle
on-page connector
Connects the processing flow on the same page; its usage avoids lines crisscrossing a page
DFDs vs. Flowchart 1
DFDs •Four symbols •Leveled sets, each depicting more detail than the last •Processes are numbered in the following formats: level zero 1.0, level one, 1.1, level two, 1.1.1 Flowcharts •Many symbols •Columns representing areas of responsibilities •Numbers are used for on-page and off-page connectors
DFD's vs. Flowcharts*
DFDs: Focus on data the how they move between business processes, external entities, and data stores - Lines represents data; they are labeled with noun phrases Flowcharts: Concerns with data, documents, and processing tools - Lines represent movements between processes areas responsibilities; not
Leveling and Balancing
Data flow diagrams are prepared in leveled sets. •A leveled set: a collection that models related business processes. The various levels provide increasing detail about the process in the system •Each level reveals more detail than the one before it •Levels must be balanced, which means that external entities and data flows at the boundary cannot "disappear" between levels.
4 Symbols for Flow Process Chart
Data: Symbols for databases and documents Process: Symbols for following the flow Line: Symbols for following the flow Special: Various symbols, such as terminators and page connections
What of the labels would you expect to find inside symbol J By Date By Name Either by Date or Name Neither by date nor by name
Either by Date or Name
In the Partial Flowchart "D" Should be replaced with? Generic or predefined process symbol A predefined process or document symbol A generic process or decision symbol A decision or document symbol
Generic or predefined process symbol
Context Diagram
Highest-level DFD; a summary-level view of a system, showing the data processing system, its input(s) and output(s), and their sources and destinations.
In the Partial Flowchart "A" Should be replaced with? Human Resources Department Applicant Human Resource Process Any of these
Human Resources
Manual Process
If it doesn't involve IT, you can use this symbol instead
Off-page connector
Off-Page Connector shows continuation of a process flowchart onto another page.
a visual display of data
Outcome will be shown on a computer screen, not paper
Document
Paper or electronic; always should have a clear point of origin and termination
System Flowchart
Provides a big picture (This is always used) Often used in AIS understand business processes Combined all resources with related processes
In the Partial Flowchart "b" Should be replaced with? Qualified Applicant Human Resource Process Any of these
Qualified
Vendor
Recentagle
Bank
Rectangle
In the Partial Flowchart "C" Should be replaced with? Applicant Name Position Description Rejection Letter File application materials
Rejection Letter
Vendor file
Set of Parallel Line
Predefined Process
Shows use of a predefined function often with parameters; multiple steps "Complete the accounting cycle"
Database
Use this symbol when data is stored/retrieved electronically
annotation
Used to add descriptive comments or explanations
A circle in a data flow diagram represents
business process
Disburse cash
circle, a process
Why it is necessary to learn both
first use DFD to focus on the data and how they are manipulated•
Document Flow chart
illustrates the flow of documents and data among areas of responsibility within an organization - Used sometimes in AIS to CHECK and IMPROVE document processing Documents include: invoices, Checks, Remittance Advice
Program Flowcharts (Almost never used in AIS)
outline the processing logic of computer programs as well as the order in which processing steps take place
data store (DFD)
represents data at "rest"--created/updated/added data to some type of file. Does not indicate how data is stored. - Noun, place to collect data - Linked to processes/external entities - Cannot be linked to one another
Purchase/Inventory File
set a parallel lines
Hardware flowcharts (rarely used)
show the computers, printers, monitors, input devices, and other hardware elements associated with an information system
decision symbol
the diamond in a flowchart; used to represent the condition in selection and repetition structures. ONLY IN A BINARY OUTCOME with two options only
Balancing
· external entities and data flows at the boundary cannot "disappear" between levels. · the data flows into and out of an external entity are the same between levels