parfor K = 1 : 4
if K == 1; Pump1; end
if K == 2; Pump2; end
if K == 3; Pump3; end
if K == 4; Pump4; end
You can also use spmd and test labindex()
It is also possible to generalize to a series of functions whose handles are given. However if you do that then you need to be sure to add those files to the parallel pool; otherwise the workers will not be able to find them through the handle. The code I show above is not pretty but it has the advantage that parfor can see the files clearly and so would know to make them available.
Note: if the routines do arithmetic computation on reasonable sized matrices, you might find that the overall result is slower than if you had executed them in sequence. By default each parallel worker only gets access to one core, but MATLAB tries to run "sufficiently large" array calculations in parallel, and that parallel operation can end up being more efficient than doing several unrelated things at the same time.