You have to translate the information you have gathered into system-oriented objectives for each transaction category. Such objectives include statements about the transaction volumes to be supported (including any peak periods) and the response times to be achieved.
Any assumptions that you make about your installation must be used consistently in future monitoring. These assumptions include computing-system factors and business factors.
Computing-system factors include the following:
Response times can vary for a number of reasons, and the targets should, therefore, specify an acceptable degree of tolerance. Allow for transactions that are known to make heavy demands on the processor and database I/O.
To reconcile expectations with performance, it may be necessary to change the expectations or to vary the mix or volume of transactions.
Business factors are concerned with work fluctuations. Allow for daily peaks (for example, after receipt of mail), weekly peaks (for example, Monday peak after weekend mail), and seasonal peaks as appropriate to the business. Also allow for the peaks of work after planned interruptions, such as preventive maintenance and public holidays.