Each factor defining the required performance should be specified in terms that are as objective as possible. Thus, where appropriate, numerical information should be given, terms must be explained and vagueness avoided.

Factors to be considered are:

• Duty/Service factor
• Nominal power
• Nominal speed
• Nominal speed ratio
• Belt length
• Power factors
• Number of belts
• Other

Note that estimates of speed and speed ratio should be used at at early stage to Select a suitable belt type . This initial Selection procedure should be implemented before a detailed investigation of requirements is undertaken, since it directs the designer's efforts in an appropriate direction.