But, having all these items in place is not enough. At the heart of success for achieving
good response time is something called the “standard work unit.”

So what is response time? Fig. 7.2.1 shows the elements of response time.

Fig. 7.2.1 The elements of response time.

Response time is the amount of time from the moment of the initiation of the transaction
until the moment in time when the results of the transaction are returned to the end user.
Fig. 7.2.1 shows that the transaction is initiated, the transaction is sent to the processor,
the processor commences execution, the processor goes out and finds data, the data are
processed, and the results are sent to the end user.

Typically, all of this activity occurs in a second or less. Given all the activity that takes
place, it is a wonder that it occurs as fast as it does.

An Hourglass Analogy

In order to understand how good response time is achieved, it makes sense to study an
hourglass.

Consider the hourglass shown in Fig. 7.2.2.

Chapter 7.2: The Standard Work Unit