งานนำเสนอเรื่อง: "1 Input designing Objectives • Discuss the objectives of systems input design • Explain the differences among data capture, data entry, and data input."— ใบสำเนางานนำเสนอ:
1 Input designing Objectives • Discuss the objectives of systems input design • Explain the differences among data capture, data entry, and data input • Explain the differences between batch and online input • List and describe the different types of data validation checks • Discuss effective source document design • Design input records • Discuss guidelines for effective screen design • Describe and design data entry screen, process control screens, GUI, and help screens • Discuss input control techniques
2 Introduction The quality of the output from an information system is directly related to the quality of its input. Input design encompasses all the activities that help to ensure the quality of the systems input. Today’s systems analysts can choose from an amazing array of input media and methods. • Keyboard • Terminal • Mouse • Touch screen • Graphic input device
3 • Voice input device • MICR reader • Scanner/optical recognition device • Data collection device Input design objectives Input design includes the development of procedures and specifications for all aspects of data capture, data entry, and data input. Data capture refers to the identification and recording of source data. Data entry is the process of converting source data into a computer-readable form. During data input, the computer-readable source data is actually input to the information system.
4 The input design process for a given information system includes the following six activities. 1. Design or modify source documents for data Capture 2. Determine how data will be entered and input 3. Design input data records 4. Design data entry screens 5. Design user interface screens 6. Design audit trails and system security measures
5 The goal of all input design activities is to enable the IS users to provide high- quality data to the system in an efficient manner. The following objects will help you meet that goal: • Utilize appropriate input media and methods • Develop efficient input procedures • Reduce input volume • Reduce input errors
6 • Utilize appropriate input media and methods Perhaps the most obvious input design decisions you must make involve the selection of input entry methods and media. Input methods are classified as either batch or online. Current trends are toward online input methods, in which data entry is performed online, interactively with the computer. • Develop efficient input procedures As you develop your input design, you must recognize points in the input process where delays could occur. A good input design avoids potential bottlenecks. For example, if one specific person must approve all orders before they are released for data
7 entry, that approval process might create a bottleneck. Most input bottlenecks occur at the data entry stage. Designing efficient and easy-to- use source documents, capturing data at its source, reducing input volume, and streamlining data entry procedures are among the measures that can reduce the likelihood of data entry bottlenecks. • Reduce input volume To reduce input volume, you must reduce the number and size of data item values that must be input for each transaction or entity. The following four guidelines help to reduce input data volume.
8 1. Input necessary data only. 2. Do not input data that can be retrieved from system files or calculated from other data. 3. Do not input constant data. 4. Use codes. BUSINESS CODES •Serial - based on arrival time •Sequential - based on an ordered table •Block - based on range of letters/numbers •Alphabetic - based on an abbreviation or other convention •Group - any combination of the above four
9 SERIAL BUSINESS CODES BANK 1 2 3 4 Based on Arrival Time - “first come, first serve”
10 SEQUENTIAL BUSINESS CODES BANK 1 2 3 4 Based on “meaningful organization” - sorted 1 2 3 4 Bob Stan Sharon Carol This example: sort by first name, then assign a number
11 BLOCK BUSINESS CODES BANK Based on a range of letters and/or numbers Bank Customer Types Merchant/Business A0001 - E9999 Personal Checking F0001 - M9999 Personal Saving N0001 - T9999 Custodial U0001 - Z9999
12 ALPHABETIC BUSINESS CODES Based on an abbreviation or some other scheme STATES UNITS OF MEASURE AZ = Arizona CA = California MI = Michigan NY = New York etc.... GA = Gallon QT = Quart PI = Pint YD = Yard FT = Foot IN = Inch etc...
13 Example: Use of a Group Code in a Paint Store Product Class Base Color Base Type Unit of Measure Legend P = Paint S = Stain 100-199 = Browns 200-299 = Greens 300-399 = Blues 400-499 = Yellows 500-599 = Reds 0 = None 1 = Lacquer 2 = Water 3 = Oil Paint Product Examples: S 206 2 G P 399 1 Q S 547 0 P P 286 3 G GROUP BUSINESS CODES P = Pint Q = Quart G = Gallon
14 • Reduce input errors Reducing the number of errors in the input data will certainly add to the quality of the data. All the efforts we have discussed previously to reduce input data volume will help reduce errors. The customer name cannot be misspelled if it is not entered. Similarly, an outdated item price cannot be used mistakenly if item price is retrieved instead of input. Good input design can also help reduce errors. As we will see when we discuss source documents, a document’s layout, captions, and instructions can be designed to make the data capture and data entry processes easier and more error- free. Well-designed screen layouts also help reduce error rates.
15 • Reduce input errors (cont.) Even with the best input designs and procedures, input errors will occur. The final defense against erroneous data entering the system is catching and correcting the errors as they are input. At least eight types of validation checks can be applied to data. • Sequence checks • Existence checks • Class checks • Range checks • Reasonableness checks • Validity checks • Combination checks • Batch controls
16 Source document design Paper documents are still commonly used in all aspects of business for collecting, circulating, and storing information. In this section, we examine source documents, those forms that elicit and capture data for input to an information system, serve as an authorization or trigger for input action, and provide a record of original input data. During systems input design, you will have the opportunity to design new source documents or modify existing source documents. You will want to design documents that fulfill their purpose and are easy to fill out, easy to use, attractive, and no more expensive than necessary.
18 Line Captions On the line: Last Name First Name Birth Date / / Telephone ( ) Above the line: Last Name First Name Birth Date Telephone / / ( ) Below the line: Last Name First Name / / ( ) Birth Date Telephone Combination: Name Last First Birth Date / / Telephone ( ) month day year area code number Boxed Captions in the box: Below the box: Last Name First Name Check Off Horizontal: Freshman Sophomore Junior Senior Vertical: Enter your class status: Freshman Sophomore Junior Senior Last Name First Name
19 The order of appearance of logical groups of information on a form is important. The majority of source documents include most, if not all, of the zones shown in figure. HEADING ZONE CONTR OL ZONE INSTRUCTION ZONE AUTHORIZATION ZONE TOTAL S ZONE BODY ZONE •Source documents –Form zones •Heading zone : ส่วน หัวกระดาษ •Control zone : ส่วน ควบคุม •Instruction zone : ส่วนคำแนะนำ •Body zone : ส่วน เนื้อหา •Totals zone : ส่วน สรุป •Authorization zone : ส่วนการให้อำนาจ
21 KMUTT Student Number Semester/Year Last Name First Name Initial Local Telephone Number Date Street Address City State Zip Course Section Subj. Number (A, A1, 01) Cr Days Times Room Bidg. Total Credits = Date Received/Initial Advisor Approval Date REGISTRATIO N FORM
22 BATES VIDEO CLUB - VIDEO RENTAL FORM Member Number Date Title ID# Rental Fee Date Returned Total Rental Amount: I agree to return the above rented videos within seven (7) days. Signed:
23 Input record design Batch data is input to a computer system in groups, or batches. During the data entry process, batch data must be placed in a temporary file; that temporary file then becomes the input file during the actual data input process. You can use a word processor or a data dictionary to document the formats of the batch input records you design. You can also use an input record layout chart to describe the format of all records in a batch input file. Whichever documentation method you use, these record layouts are used by programmers during system development; if the data will be keyed by data entry clerks during system operation, they could use the same record layout documentation.
24 Record : Student Record Studen t_ID Student_ Name Adv_Na me Adv_Ro om Class # Unus ed 1-45-3435-6465-6768-7374-80 9999X(30) 9999999 99 X(7) Record Name Field Names Position Data Type Input record layout for the student registration form Record Type Student Number Semester Year First 4 characters Of Last Name 12345678901234567890123456789012345678 9012345678901234567890…………
25 SYSTEM DOCUMENTATION NAME OF SYSTEM DATE PAGE 1 OF 1 REGISTRATION 2/17/97 ANALYST PURPOSE OF DOCUMENTATION M. Friedman Registration Input Record Layouts STUDENT RECORD - One record is created for each registration form FIELD TYPE POSITIONS COMMENTS REC TYPE A 1 = “S“ for a student record STUDENT NUMBER N 2-7 SEMESTER A 8 = “F“ for Fall, “W“ for Winter, “S“ for Summer YEAR N 9-10 Last two digits of the year NAME X 11-14 Only the first four characters of the Last Name are entered COURSE RECORDS - One record is created for each course on the form FIELD TYPE POSITIONS COMMENTS REC TYPE A 1 = “C“ for a course record SUBJ A 2-4 Standard department abbreviation COURSE NUMBER N 5-7 SECTION X 8-9 Left-justified Input record documentation for the student registration form
26 BAXTER COMMUNITY REGISTRATION FORM 137426 F / 97 COLLEGE Student Number Semester/Year SANDERS KIMBERLY M 458-1203 5 / 5 / 97 Last Name First Name Initial Local Telephone Number Date 1701 W.EMBERS DRIVE HAMPTON NH 03842 Street Address City State Zip Subj. Course Section Cr Days Times Room Bidg. Number (A, A1, 01) ENG 120 E 3 M W F 10 - 11 211 CON MTH 125 B 5 M T W Th F 9 - 10 103 BAX CS 150 C 3 T Th 10:30 - 12 119 BAX PHI 212 A 3 M W F 2 - 3 110 AUG PE 103 C1 2 T Th 3 - 4 GYM 5 / 6 / 97 SM S. Cantez May 5, 1997 Total Credits = 16 Date Received / Initial Advisor Approval Date student record course records Data entry information flow for the student registration form
29 Screen design We will now complete our coverage of screen design by discussing design principles for data entry screens and all types of user interface screens. All screen displays serve the same two general purposes: to present information and to assist the operator using the system. As you might expect, many of the design guidelines we discussed for output screens are also applicable to data entry and user interface screens. These guides are, therefore, worth reconsidering. 1. All screen displays should be attractive and uncrowded
30 2. The information on a single screen should be displayed in a meaningful, logical order. 3. Screen presentations should be consistent; that is, screen titles, messages, and instructions should all appear in the same general locations on all types of screen displays. 4. All messages, including error messages, should be explicit, understandable, and politely stated; avoid messages that are cute, cryptic, or insulting. 5. Messages should remain on the screen long enough to be read. 6. Special video effects should be used sparingly. Color, blinking, high brightness, reverse video, and sound effects all can help attract the operator’s attention;
31 but the overuse of such effects distracts rather than focuses an operator’s attention. 7. Feedback is important. 8. As was true for output screen designs, all input screen design layouts should be documented on a screen display layout form for later use by programmers. • Data entry screen design Form-filling is the traditional technique for online screen data entry. In form-filling, a complete form is first displayed on the screen; the operator then fills in the form by entering data, field by field.
32 A simple data entry screen. The operator is in the process of entering a project description.
38 • Process control screen design In many information systems, some or all of the system processing is designed to execute in an online mode in response to requests entered by end users. For such online systems, you must design appropriate input screen for entering the end user processing requests. These screen displays are called process control screens, or dialogue screens. Two processing control methods are commonly used: menu input and prompted input. • Menu screen
41 • Prompt screen Do you wish to add, edit, delete, display, or print records? >ADD What source document will be used to add the records? >REGISTRATION A question/answer screen sequence • Combination screens Menu input and prompted input are often used in combination.
42 MAIN MENU 1. Student Score Processing STUDENT SCORE PROCESSING MENU 1. Add a set of scores 2. Edit a set of scores 9. Return to Main Menu 2. Class List Processing CLASS LIST PROCESSING MENU 1. Add a new class list 2. Edit a class list 9. Return to Main Menu 3. Report Processing REPORT PROCESSING MENU 1. Print reports without dropped scores 2. Print reports with dropped scores 3. Print a score date entry form 9. Return to Main Menu 4. History Processing HISTORY PROCESSING MENU 1. Add a class to the history file 2. Search for a specific student 9. Return to Main Menu 5. Class Setup Processing CLASS SETUP PROCESSING MENU 1. Add/Edit grading scale 2. Add/Edit score descriptions 3. Add/Edit maximum scores 4. Edit a student’s final grade 9. Return to Main Menu 6. System Configuration CONFIGURE SYSTEM MENU 1. Configure entire system 2. Configure monitor and colors 3. Configure printer 4. Configure disk drive 9. Return to Main Menu 9. Exit System
43 • GRAPHICAL USER INTERFACE (GUI) DESIGN The most recent evolution in screen design involves graphical user interfaces. A graphical user interface (GUI) Uses windows, menu bars, pull- down and pop-up menus, and graphical pictures (call icons) with which the end user communicates with the application system.
52 Common GUI Controls Uses •Text boxes –When the input data values are unlimited in scope •Radio buttons –When data has limited predefined set of mutually exclusive values •Check boxes –When value set consists of a simple yes or no value •List boxes –When data has a large number of possible values •Drop down lists –When data has large number of possible values and screen space is too limited for a list box •Combination boxes –When need to provide the user with option of selecting a value from a list or typing a value that may or may not appear in the list •Spin boxes –When need to navigate through a small set of choices or directly typing a data value
53 Common GUI Controls (Windows and Web) •Text boxes •Radio buttons •Check boxes •List boxes •Drop down lists •Combin ation boxes •Spin boxes •Buttons
54 Advanced Controls (mostly Windows interfaces) •Drop down calendar s •Slider edit controls •Masked edit controls •Ellipsis controls •Alternat e numeric al spinners •Check list boxes •Check tree boxes
55 Advanced Controls (mostly Windows interfaces)
56 • Help screen design Even with the best of online input processing designs, end users might occasionally require additional assistance or information. Online help screens display a window or screenful of text that explains concepts, procedures, menu choices, function keys, formats, and so on. End users typically request help in one of two ways: by pressing a special key (usually one of the function keys) or by clicking a command button, tool bar button, or menu option designated for that purpose. Many information systems use both techniques. Help information is typically presented in two different ways:
57 • Context-sensitive help • A help switchboard or menu is displayed whenever an end user requests help Both techniques just described can be useful, and they can be use in combination. Many information system provide both context- sensitive and menu-driven help. SEMESTER field Help The allowable values for Semester and their meanings are as follows: Value Meaning F Fail W Winter S Summer Close Main HELP Topics Student Score Processing Class List Processing Report Processing History Processing System Configuration Close
58 Switchboard for Student Registration System : Form
59 An example of switchboard and data entry form for a project management system
60 • Input control Input control encompasses all measures necessary to ensure that input data is correct, complete, and secure. As we stated earlier in this chapter, this topic cannot be treated as a mere afterthought. You must consider input control throughout all aspects of your system input design. We have already discussed many of the measures you can take to ensure that input data is correct and complete. Effective source document design promotes both correctness and completeness. For batch input, critical source document fields can be pre-checked during data capture, and batch control totals can be used during data input. During either online data entry or
61 batch data input, you can validate all data fields. Your online data entry program can simply refuse to accept invalid field values; your batch data input program should write all rejected records to a log file, which then must be periodically checked for rejected records that have not been corrected and re-input. Data security also involves protecting data from unauthorized access. System sign-on procedures should be developed to help prevent unauthorized individuals from accessing the system. Data files should be given passwords; especially sensitive data can be encrypted, or coded, so that it cannot be read except by special decoding software.