Tandem Capacity Model (TCM) Manual

perform such operations as finding all samples where the throughput of transaction Txn 1 is
greater than 10 transactions per second.
3. History Data—Not directly modifiable
History Data is the historical sample data as apportioned by the WA model. This data is
loaded by selecting Update History from the History tab and cannot be modified. Performance
data is sorted by apportionment method and transaction type in descending date sequence.
Significant Columns
4. App’t—Not directly modifiable
App’t is the apportionment method that was used in the WA model to compute the sample
performance data from the MeasTCM process category data. Because Capacity History can
be updated with data from more than one apportionment method, the same sample could
appear more than once, each occurrence being generated with a different apportionment
method.
5. Mix—Not directly modifiable
This column shows the percentage mix of transactions in the sample used. Carefully note the
mix. The mix of transactions must vary for your model to be reasonable.
History Charts
The Chart History command creates two types of History charts from the History file, Trend charts
and Mix charts. Trend charts and Mix charts are placed on worksheets named TrendCharts and
MixCharts, respectively, in the History file workbook.
The Chart History command is available whenever a History file is in the session. If a History file
currently appears, the Chart History command applies to the displayed History file. Otherwise
TCM performs a TCM Find to the History file if there is only one History file in the current session.
If more than one History file is open in the current session, you are prompted to select one from a
list, after which TCM performs a TCM Find to the selected History file. The Chart History command
then applies to this History file.
To create a Trend chart or a Mix chart:
1. Open a Workload Apportionment model.
2. Open a History database:
• If a History database already exists, open it.
• If a History database does not exist, select History Update History to create a History
database. The History database must exist before TCM can create a chart.
3. Choose History Chart History.
• If the History file contains data for more than one apportionment method, TCM prompts
you to select the apportionment method you want to use when creating the History charts.
• If TrendCharts, MixCharts or both are already part of the History file, the History Chart
Overwrite Warning dialog box appears. To create new Trend charts and Mix charts (the
existing ones are deleted automatically), click both boxes. This action is recommended.
Clearing either check box causes TCM to not overwrite that Chart sheet. When you finish
making your selections, click OK.
4. When the History Charts dialog box appears, choose a chart size: 1/4 screen, 1/2 screen
(horizontal), 1/2 screen (vertical), 2/3 screen (the default), or Full screen. Then click OK.
TCM creates the requested History charts in the specified size. Progress messages appear in
Excel's status bar at the bottom of the screen while the History charts are being created.
124 Workload Apportionment Model