Ok, I'm not sure I'm using the correct terms for the tense. What I'm describing is what I was taught for style in doing reports about procedures.
When you write a procedure for persons to follow, you write it in a "do this then this" tense. I'm not sure the correct name for it, but I call it "immediate" tense. You write from the point of view of the person(s) doing the procedure, as though you were there at that immediate instant. "Task 1: Apply these conditions. Test that it is correct by looking for these indicators in this range. If these indicators don't appear within 30 seconds, abort and stop. When the indicators appear, move to the next task. Task 2: Push the button labeled Heat." And so on.
Try to keep these sorts of procedures as simple as reasonably possible. For example, try to avoid things like "you are going to see" or that sort of construction. Try to make it always "Do this. Then do this. Look for this. If you see it, continue, otherwise something is wrong and abort."
If you are now writing a report and want to include the procedure, you could write the procedure as a chapter, with an intro to the effect that "This chapter gives the procedure that was followed when the experiment was performed." Or possibly you could make it an appendix or some such. Or "that will be followed" if it is a planned task for the future. Or "that is followed each time the test is performed" if that is appropriate. Then put in some kind of marker indicating "procedure starts here" and "procedure ends here."
When you write about a task that will be completed in the future, you use a future tense, but point at the procedure. And you always say things like "will be completed" or other definite terms. "When this task is completed it will follow procedure WD-40." And then that procedure is written "immediate" as before.
When you report on a task that has been performed you write in a sort of past-perfect tense. By that I mean, you write with the idea that the task was performed in the past, and it was completed. "The task described in Procedure WD-40 was performed on 14 February 2016. The reported results obtained from Plan WD-40, Task 1, are as follows." Or if it messed up somehow you say something like "Task 14 was begun in sequence according to procedure WD-40. However, the required indications failed to appear, so the procedure was aborted."
For tests that have already been done, avoid saying things like "will be completed" or "was supposed to be completed according to plan WD-40."
When you refer to another part of the same document, say things like "is discussed further in Section 4.3" or "is discussed further in following sections." Avoid saying things like "will be discussed further in following sections" because it looks like you are planning to do it but have not yet.