Understanding the rate and number of transactions probably on a real system is critical to ensure that the system is designed well and later sized and deployed well. Good understanding of the business domain is seen as a key enabler to arrive at the usage profile.
Operational profiling (A STEM core concept) is a scientific way to quickly arrive at a real life profile of usage. Good understanding of this concept alleviates the problem of lack of deep domain knowledge to understand the usage profile. This core concept consists of these key aspects:
- Mode – Represents a time period of usage e.g. End of month, where the usage patterns are distinctive and different.
- Key operations (features/requirements) used
- Types of end users associated with the key features/requirements
- Number of end users for each type of users
- Rate of arrival of transactions
In short, for a given mode, identify the end users types and their key operations and then identify the number of users for each type of user and then identify the rate of arrival of transaction. Employing this core concept allows us to think better and ask specific questions to understand the marketplace and the usage profile in a typical and worst-case scenario.
This allows us to get a better understanding of the usage and helps in identifying business risks and derive an effective strategy.