Map resources around non-moveable projects

- Quite a simple idea, but one that only occurred to me after quite a few years is to base your plan around the projects that can't be moved. Of course, nobody wants their project to be moved. Everyone has an ideal delivery date when they want it. But in reality, there are some that have some flexibility and some that really do have to be done by a particular date. For some reason, I'm thinking about my daughter's wedding dress and wedding cake, but I could also give the Olympics as an example of a time critical project. Or any project that requires a bid to be put in. Or maybe has a seasonal element, like marketing for the Christmas sale period. Or preparing for an exhibition. So if we list all of the projects that can't be moved and draw them out on the Gantt of Gantts in the right places for them, we can add up the resources, either the total of all the resources we have, or the total amount of bottleneck resource for just these projects. Then, if we take this required resource away from the total that we have, we can see how much we have left for all of the other projects, all of the movable ones. Let me illustrate that for you with this graph. Suppose IT is our bottleneck resource. Every project needs IT. And we only have eight IT people available for the various projects we want to do. The first thing to do is to add up how many IT people we need for the projects that can't be moved. And suppose we need six people to start with, and the number gradually dwindles away with time until we have all eight people available again at some point in the distant future, this is the line on my graph here. You can, on the pink line on the graph, see that initially we only have two of our eight people available because the other six are on the can't be moved projects. And as those projects finish, the people are gradually freed up and we get up to six available, then a few are used again so we're down to four, but eventually after 20 weeks, we get all eight available again. And remember that this might not be people becoming available, it could be any resource like trucks or cranes or laboratories or meeting rooms. And also, if it is people, it could be the total number of people on your projects, not just the ITs, whatever you need to focus on. So the pink line is how many people you have available gradually increasing as they come free from the fixed projects. Then there's the blue line, which is the amount of work you need to do. To be more precise, it's all the movable projects added up. You can see that the movable projects add up to a requirement for six or seven people to start with, but as time goes on, they dwindled down to four. Meanwhile, my problem is that the resource I have available, the pink line, is only two people to start with. As we've seen, it does gradually go back up to eight as the can't be moved projects gradually finish. But my problem for the first 11 weeks is that I have many more movable projects, the blue line, than the resource available. And it's really only from week 20 onwards that I have enough people to cope. So I need to shovel all this movable work, this overwork, from the first nine weeks into weeks 20 onwards. So we know how much movable work we're trying to do and also how much resource we have left after accounting for the non movable work. I found that when I've done this for real for organizations that often these movable projects end up sliding a long way out into the future, which is a bit of a shame. But if you don't have the resources, then you just don't. So which of your projects can't be moved? What proportion of your projects is that? And when you add those up, how many resources do you have leftover for all your movable projects? And is it enough?