Your project is costing you more than you think
Stakeholder time, opportunities, intellectual capital — these are just some of the unseen and untracked costs you are expending throughout the life of your project.
One that might be worth you keeping track of above all else though is goodwill. It is very easy to take advantage of certain people in order to get your project delivered as, after all, projects are delivered by and through people so it is not too surprising. This being said, it could be worth your while thinking about how you use those people to the best effect in the long term. Asking your technical lead to pick something up "as a favour" may ultimately have spent the last of your goodwill on something that could have been better placed elsewhere in your project team.
Consider the scenario where you are working with a supplier and something goes wrong. Under the contract between the parties, it is clear that they have no obligations to do anything about the situation. Perhaps it is the fault of a third party and you are seeking some goodwill from a delivery partner (aka supplier) to help resolve the situation. If the relationship is good and it might be in the overall interest of the delivery partner to facilitate a resolution then they may assist, this, of course, assumes that the reward is well aligned with outcomes, but in the situation where you have used up the last of your goodwill on a small change earlier in the project where you sought their 'pragmatism' and the fact that you needed the change to happen without being jammed up in a lengthy negotiation process.
Perhaps this is starting to sound all too familiar now.
So what do you do about this? It may perhaps be considered too onerous to maintain a 'goodwill log'. In fact, this starts to formalise a decidedly informal way of working and with the wrong behaviours could result in "you owe me a favour". Perhaps it is better to consider how to ensure you are not taking advantage of one particular party and keep yourself in check. This can promote healthy working relationships and ultimately should lead to outcomes being achieved more easily through honest and open communication. It is worth opening up a line of dialogue with your team about what they are doing, not from a mechanistic point of view but from an 'appropriateness' perspective, ensuring that you are not overburdening some areas of the team but also not misusing skills to deliver tasks that could be more optimally delivered elsewhere within the project.
At the very least, start thinking about the real cost of your project as although the iron triangle of time, cost and quality (or scope depending upon your school of thought) is prevalent in academia — it does not reflect the true cost of project delivery.