Transaction billing charges for work in units that are meaningful
to the user. Transaction units can include runs of a particular program,
online invocations of a defined function, or records read or printed
by a standard application. Bills based on transaction units show
a clear relationship between the service requested and the payment
due, a relationship that, for TSO/E and IMS™,
is not apparent from a list of resources actually consumed.
Techniques of specifying storage allocation, for instance, are
not visible to many terminal users, who therefore have trouble relating
their actions to a charge for storage hours. However, charging in
terms of commands used is clear to the terminal user.
Transaction billing helps users to see the correlation between
what they do and what they pay. With this information, they can develop
cost-effective operating standards. If transaction prices incorporate
the average cost of resources consumed, the users can evaluate alternatives
and make decisions based on their own operations.
Transaction billing might include billing for the use of some TSO/E
commands. To be suitable as a billing unit, a transaction should involve
processing costs that are consistent enough over time for the average
to be meaningful. The transactional billing data collected for TSO/E
is how many times each TSO/E command is issued. Note that a TSO/E
command does not relate to the system resources manager (SRM) definition
of a TSO/E transaction as described in z/OS MVS Initialization and Tuning Guide.
The following steps can be used to develop a method of transaction
billing for the use of TSO/E commands:
- Determine the TSO/E costs you want to recover. To determine the
TSO/E cost, summarize the total installation cost and then allocate
part of it to TSO/E. You can obtain a gross allocation ratio from
the data in type 30 records by comparing the resource consumption
for TSO/E with the overall resource consumption.
- For each type of TSO/E command, measure the average resource consumption
and the number of times the command is used over a representative
time period. You can obtain this data from SMF record type 32 (with
the DETAIL option). For further discrimination, you can break down
the calculations to the specific user ID.
- Based on the number of commands issued (obtained during step 2)
and any other relevant information, predict the command use by type
(for a billing period).
- Set rates for the resources measured in SMF record type 32, so
that the use predicted in step 3 recovers the TSO/E costs from step
one. That is, the resources used multiplied by the rates set for the
resources should equal the cost you recover.
- Set prices for each type of TSO/E command, based on the use of
the command as determined in step 2, at the rates established in step
4. That is, divide the cost of the resources by the number of times
the command was issued to determine the price for each command type.
- For the duration of each billing period, you can use the date
in SMF record type 32 to count the commands being issued by type and
user ID. Use the prices determined in step 5 to bill each user ID
for the commands used.
- Repeat step 6 for each billing period until you recalculate the
prices. (Deciding how often to recalculate the prices represents a
trade off between accuracy and stability.) If costs have changed,
start with step 1, otherwise start with step 2.