For the purposes of a CSC 308 example, the non-functional requirements for the Scheduler Tool are organized into these categories and subcategories:

• performance
• general characteristics
  • Security and Privacy
  • Simplicity versus Power

All resource/preference management, viewing, and options commands must execute instantaneously, except for the following:

• the time to generate a new schedule must be on the order of minutes
• the time to execute viewing an instructor's preferences must be instantaneous, except for any delays due to network transmission of data from the central host to the local computer

The time to execute all administrative commands must be instantaneous, except for any delays due to network transmission of data from the central host.

In general, the performance of Scheduler Tool commands that must access data across a network is subject to potential network delays. The Scheduler Tool must transmit data as fast as is possible on any given network, but delays due to external network circumstances are beyond the control of the Scheduler Tool.

There are no specific requirements for the allowable size of a schedule in terms of the number of resources. A Scheduler on the order of hundreds of resources is the maximum expected size during normal use.

The maximum expected sizes of the Scheduler Tool databases are the following:

• user database -- up to tens of thousands of records
• instructor database -- up to hundreds of records
• course database -- up to hundreds of records
• room database -- up to hundreds of records
• schedule database -- up to hundreds of records

The Scheduler Tool must be able to operate with schedules and databases of sizes larger than these normal maximums. However, the tool need not the meet the previously-enumerated time performance requirements for schedules or databases larger than normal maximum sizes.

3.2. General Characteristics

3.2.1. Security and Privacy

Preferences and admin settings with a security setting other than `Public' must have only the allowed information viewable to any user other than the scheduling admins. The central host passwords of any user must be kept secure from viewing or modification by any other Scheduler Tool user, and from any user at all on the central host.

3.2.2. Simplicity versus Power

On a spectrum of simple-to-use versus powerful, the Scheduler Tool is heavily on the side of powerful. Users are assumed to be fully computer literate and knowledgeable on the use of computer networks consisting of local computers and central data servers.