Nineteen PROP instances with number of facilities in {16, 20, 21, 22, 23}.

These instances were introduced in [1] for the parallel row ordering problem (PROP), but they can be used to test other row layout problems, e.g. the single row facility layout problem (SRFLP).
An instance of the PROP looks like a SRFLP instance with an additional parameter t.
Thus, for each SRFLP instance with n facilities, assume that the first t facilities given in its datafile are to be restricted to Row 1, while the other (n - t) facilities are restricted to a parallel row (Row 2).
Here, there are two instances with n=16, two instances with n=20 and five instances for each n in {21, 22, 23}. Set the parameter t as needed.

In [1] tests are done with t in {floor(n/2), floor(n/3), floor(n/4), floor(n/5)}.

1. Amaral, A.R.S. (2013) A parallel ordering problem in facilities layout. Computers & Operations Research, 40(12): 2930-2939. https://doi.org/10.1016/j.cor.2013.07.003.