Tandem Capacity Model (TCM) Manual

c. Select the CSV sample data files to be used by selecting the files and clicking either the
Remove or Add buttons. To select multiple files press the Shift or Control keys while clicking
the file names. Press the Shift key to select a contiguous set of file or files. Use the Control
key to add or remove a highlighted file.
d. If you want to get information about a CSV file before you decide whether to use it, select
the CSV file name and click the CSV Info button. The CSV Info dialog box appears.
The Number of Transactions field shows the total number of transactions of the type
selected in the Transaction field. The Transaction Mix field shows the percentage of
transactions in the CSV data of the transaction type selected in the Transaction field.
From this dialog box, you can also select a different transaction or Transaction Count
table. As you change the selected transaction or Transaction Count table, TCM updates
the information in the dialog box of your choice.
4. Once you have completed the fields in the Generate Apportionment Weights dialog box, click
Generate.
TCM Expert generates an Apportionment Weights table and a confirmation dialog box
appears.
5. Click OK or press Enter to close the confirmation dialog box.
• If TCM Expert has too few CSV files, a dialog box reports this fact, and TCM Expert stops.
• If TCM Expert does not have enough CSV files or has wrong transaction counts, a
transaction list shows the transactions that TCM Expert does not have consistent costs on.
• If TCM Expert finds that the CSV files are not compatible with the .AWA files, an
incompatible CSV list dialog box appears.
• If TCM Expert finds CSV files that are correlated, a linear relationship dialog box appears.
• If TCM Expert finds transactions that do not occur in any of your CSV files, TCM Expert
displays question marks (?) in the Apportionment Weights table and does not include
these transactions in its analysis.
6. Examine the Apportionment Weights table generated by TCM Expert.
To override TCM Expert’s calculations for any category marked with a Y:
a. Select Options > Unprotect Admin Fields. TCM makes modifiable fields available.
b. Type an N in the Expert Flag column of the category you want to override and enter the
values you believe are correct under the transaction columns.
c. Reprotect admin fields.
d. Go to Step 1 and generate again.
TCM automatically updates capacity history using the automatically generated Apportionment
Weights table.
Using the Consumption Model
The TCM Consumption model is used primarily to predict the number of CPUs and logical disk
volumes required for a given scenario. The capacity planner can specify any of the following
parameters:
• Target online CPU utilization, disk utilization or both expressed in average percentages
• Target online host response time in seconds (either average or percentile)
• Target batch response time
• Planned online throughputs in transactions per second, hour, day, or month
• Planned CPU and disk type
• Number of CPUs and/or logical disk volumes, or both
• Planned number of transactions per task for batch transactions
To use the Consumption model:
250 Common TCM Procedures