It's a very important question, but it's an exceedingly complicated one because of the range of different programs and the different timetables they are on.
Your point about line by line is an important starting point. Parliament controls spending by aggregating a whole bunch of initiatives into a vote, so we do not itemize all the different spending of departments by program or by project. It is aggregated, and part of the reason the vote wording is so obtuse is to account for all the different complexities of these programs.
Underneath that, there is a great deal of control by Finance and by Treasury Board for each program and project. They're evaluated. They're reviewed. There are some that sunset, because they were designed to sunset.
There are some that lapse money; they couldn't come to an agreement with a partner or a stakeholder or another jurisdiction, and then a decision is made by Finance. They ask, what do we want to do? Do we want to move that money into a new year and pursue the initiative? We then say that the money lapses, and when it is brought forward into a different year, it's re-profiled funding. That is presented to Parliament. If we decide to go forward with an initiative, it is included in the department's main estimates, or in subsequent supplementary estimates.