Tandem Capacity Model (TCM) Manual

3. From the Expert tab to the TCM Expert Parameters, enter in Check History Over Last the number
of months required to cover all dates when the samples were taken.
4. Select Expert Update History with Selected CSVs. The Update History with Selected CSV Files
dialog box appears. By default, the CSV files that have not yet been used to update capacity
history appear in the Selected CSV Files list.
5. Select a History database from the History Database list. Select from the list of History files,
keep the default History name, or enter a new name.
6. Select an apportionment table from the Apportionment Table list. Select from the list of
apportionment tables or keep the apportionment table name.
7. If you want, you can remove CSV files from the list or add them to it to update capacity history:
• To select a CSV file, click a file name in the Unselected CSV Files field and then click
Add. The file name appears in the Selected CSV File list.
• To clear a CSV file, click the file name in the Selected CSV File list and click Remove.
The file name appears in the Unselected CSV File list.
• To get information on a specific CSV file, select a CSV file name in the Selected CSV
Files list and click CSV Info.
8. Click Update History.
TCM Expert updates capacity history and shows the updated file.
If TCM Expert finds inconsistent transaction costs in the capacity history, it reports this
information to you in a dialog.
For more information, see “Updating Capacity History With Selected CSV Files” (page 185).
Analyzing Capacity History
The Capacity History database is a valuable tool in determining the reasonableness of the
apportionment method. From it, the capacity planner can analyze the apportioned data in each
sample model and eliminate unrepresentative sample models, as well as identify the apportionment
method that yields the most consistent CPU and disk demands.
To analyze capacity history:
1. Open a Workload Apportionment model.
2. Select Find Capacity History, Database. The Capacity History screen appears.
If the model has more than one Capacity History database, the Find Capacity History dialog
box appears. Select a Capacity History file from the Select field and click Find. The Capacity
History screen appears.
3. Analyze the historical variance of the CPU and disk demands for the sample data. Delete or
ignore unrepresentative date samples, which might have been taken when data communications
lines were inoperative or during CPU failures.
• To delete records, select at least one delete criterion in a highlighted field and then select
History > Delete History.
• To sort records, select History > Sort History, click the Sort by Transaction or Sort by
Sample button, and then click OK.
4. Select the apportionment method that yields relatively consistent CPU and disk demands across
all the representative samples.
Non-Pathway Example
The following example describes an apportionment method for a non-Pathway automated teller
machine (ATM) application.
Three major transaction types are: ATM, Non-ATM, and Foreign. An ATM transaction is a transaction
in which a bank customer performs an ATM function on an ATM that belongs to the bank. A
Non-Pathway Example 83