The very final part of the first milestone is to plan the project schedule, for this we use something called a Gantt chart. This fixes development progress deadlines using subjective time allocation (better than nothing), task linkage and allows to see the critical path. Indeed some tasks depend on others, if something takes longer than expected then it will delay all the tasks that depend on it, these tasks are critical, thus the critical path.

With a Gantt chart it is easy to understand what are the important tasks that should be focused on and what to leave for later. The Gantt chart should be opened at all times, checked regularly by all members working on the project and updated by the project manager.

You can make a project schedule using free tools such as Gantter.

In the current project nothing can be done in parallel, I admit it's not a very good example of Gantt chart application. The demonstrator can only be built when the needs, functions, etc. are done, it doesn't make any sense to jump to solutions if you don't have a good idea of what you actually need (do not confuse with "want"). Often I notice people looking for solutions for non-existing problems, that's just inefficient, usually waste of time and shows incapacity in proper project management, somebody mentioning a solution before a project has started is already a red flag (but so much more fun).

With this schedule the computers are going to be ready just in time before the departure to Malawi. Following it (and updating it often) allows to concentrate man-hours where needed and has a high probability of getting it finished within the deadline.