A Data Warehouse is required to run queries on a large table that involves full table scans. The response times for these queries are very critical. To reduce the query response times parallel query is utilized. Running one of these queries utilizes 75% of all system resources on the machine for a minute. The business requirements determine that over two hundred users need to perform this query each once about every 2 minutes. Clearly here we have problem in that this sort of problem probably cannot be solved by any machine. In this example it is possible to see where a well informed set of system designers can ensure they do not commit to deliver a business requirement that is clearly impossible to deliver.