Generally, in life, none of us wears the cheapest suit or uses the cheapest pen or lives in the cheapest house available. We've all determined that there's some combination of characteristics that provides us with the best value for the way we purchase the goods and services we buy. In the government, we try to do exactly the same thing. All the methods you've talked about are used--weighting various capabilities that the government is looking for, or perhaps using formulas that weigh that technical evaluation against price--so that at the end of the day we can determine which of the goods or services being offered provides the best value to the taxpayers of Canada.
On February 20th, 2007. See this statement in context.