Chapter 8 Flashcards
the goals of systems design is to build a system that is effective, reliable, and maintainable
a system is effective if it supports business requirements and meets user needs.
a system is reliable if it handles input errors, processing errors, hardware, failures, or human mistakes.
a system is maintainable if it is flexible, scalable and easily modified. changes might be needed to correct problems, adapt to user requirements, or take advantage of new technology.
User Interface
describes how users interact with a computer system, and consists of all the hardware, software, screens, menus, functions, output, and features that affect two-way communications between the user and the computer. The UI is the key to usability, which includes user satisfaction, support for business functions, and system effectiveness.
a data validation rules
improves input quality by testing the data and rejecting any entry that fails to meet specified conditions. the design can include at least eight types of validation rules
sequence check
existence check
data type check
range check
reasonableness check
Guidelines for designing data entry screens
- Create an interface that is easy to learn and use
- enhance user productivity
- Provide Users with help and feedback
- Create an attractive layout and design.
- Enhance the interface
- Focus on Data Entry Screens
- Use validation rules
- Reduce input volume
garbage in, garbage out (GIGO)
the best time to avoid problems is when the data is entered. The main objective is to ensure the quality, accuracy, and timeliness of input data.
source document
a source document collects in put data, triggers or authorizes an input action, and provides a record or the original transaction. During the input design stage, the analyst develops source documents that are easy to complete and use for data entry. source documents generally are paper-based, but also can be provided online,
turnaround documents
output documents that are later entered back into the same or another information system. In some areas, the telephone or utility bill, for example might be a turnaround document printed by the company’s billing system. When the required portion of the bill is returned with payment, the bill is scanned into the company’s accounts receivable system to record the payment accurately
Types of reports
When designing reports the essential goal is to match the report to the user’s specific information needs. depending on their job functions, users might need one or more of the reports
Detail reports
Exception reports
Summary reports
Detail reports
a detail report produces one or more lines of output for each record processed. because it contains one or more lines for each record, a detail report can be quite lengthy. Consider, for example, a large auto parts business. if the firm stocks 3,000 parts, then the detail report would include 3000 detail lines on approximately 50 printed pages. A user who wants to locate any part in short supply has to examine 3,000 detail lines to fine the critical items.
Exception Reports
an exceptions report is displays only those records that meet a specific condition or conditions. Exception reports are useful when the user wants information only on records that might require action, but does not need to know the details.
For example, a credit manager might use an exception report to identify only those customers with past-due accounts, or a customer service manager might want a report on all packages that were not delivered within time period.
Summary reports
Upper-level managers often want to see total figures and do not need supporting details. A sales manager, for example, might want to know total sales for each sales representatives but not want a detail report listing every sale made by them. In that case, a summary report is appropriate. similarly, a personnel manager might need to know the total regular and overtime hours worked by employees in each store but might not be interested in the number of hours worked by each employer
Output Technology
Internet-based information delivery
email
blogs
instant messaging
wireless devices
digital audio, images, and video
Output Security
protects privacy rights and shields the organization’s proprietary data from theft or unauthorized access. To ensure output security, several important tasks must be performed. First, limit the number of printed copies and use a tracking procedure to account for each copy. when printed output is distributed from a central location, specific procedures should be used to ensure that the output is delivered to authorized recipients only. That is especially true when reports should be stored in secure areas all pages of confidential reports should be labeled appropriately
Data security
data security policies and procedures protect data from loss or damage, which is a vital goal in every organization. If the safeguards are not 100% effective, data, recovery utilities should be able to restore lost or damaged data. Once data is entered, the company should store sources documents in a safe location for some specified length of time.
prototyping
produces an early, rapidly constructed working version of the proposed information system, called a prototype. prototyping, which involves a repetitive sequence of analysis, design modeling, and testing, is a common technique that can be used to design anything from a new home to a computer network.
