Minimising the number of gap-zeros in binary matrices

► We address a problem of sequencing rows of a binary matrix. ► The objective is to minimise the total number of zeros in the gaps between blocks of consecutive 1s in the columns of the matrix. ► The problem is known to be NP-hard. ► We develop an exact solution algorithm, which is efficient for small matrices. ► Two constructive heuristics provide near optimal solutions for instances of any size.