Tandem Capacity Model (TCM) Manual

◦ Disk write cache configuration
◦ Number of TMF audit trails required
• TCM Parameters—used to set various parameters for the Performance model.
• CPU Conversion Factors—used to set factors that represent the relative CPU speeds assumed
for the application or set of applications in the model.
• Baseline Detail by Category Actual—shows detailed information about process categories,
CPU consumption by transaction, category priority, disk process priority queuing, and CPU
tunability.
• Baseline Detail by Category Plan—used to view detailed characteristics about process
categories. The screen defaults to the actual data but is modifiable.
• Charts—provides presentation-quality charts of the data in the Planning Timeline model.
• Capacity History Database—a database used to archive and organize apportionment data
from the WA model. Capacity history is organized as an Excel database and presents
information that is useful to the capacity planner for such tasks as apportionment validation,
trend analysis, and selection of representative samples. This screen is available for read-only
access in the Performance model.
• Capacity History TrendChart—The Trend chart is designed so you can easily see how transaction
rates change over time from sample to sample and how the corresponding transaction cost
(CPU time per transaction) varies by sample. If a reasonable apportionment scheme was used
when adding the data to the History file, the transaction cost will not vary much from sample
to sample and should not be a function of the sample transaction throughput rate.
• Capacity History MixChart—3-D pie charts that show the percentage of CPU activity for each
named transaction consumed during a data sample.
• TCM User Customization screen—used to change the appearance of the TCM screens. The
user can change the Display/Printer font properties, the background colors, and the font color
of the Manually overwritten cells.
Each of the screen descriptions shows a sample screen and describes the significant rows and
columns.
Data Source
The source of the data for the Performance model is the Workload Summary and Workload Detail
screens in the WA model or their equivalent. To load data into the Performance model, either:
• Select Create a New Performance model from the “TCM Initial Menu” (page 66). TCM prompts
you to pick either an .SWA file or a CSV and associated .AWA file from your custom folder.
• From the TCM Expert tab, select Create Pick Best Sample. TCM loads the best sample into a
new Performance model.
NOTE: Although the WA model is the usual data source for the Performance model, you can
also directly add, change, or delete transaction data in the Performance model by selecting Add
Transaction, Delete Transaction, Add Category, or Delete Category from the Update tab. For
example, do this to model theoretical transactions for which no Measure data exists.
Navigation
To move from one screen to the next in the Performance model, select the name of the screen you
want to view from the Find tab or from a tab at the bottom of the screen.
To go to the User Customization screen, select the Customize TCM command from the Options
tab.
Data Source 137