In various circumstances, it is possible to arrive at the need to specify sequences of operations that a "machine" has to perform to achieve a purpose. This paper will present VISPS, a visual system originally designed to specify mission plans for the SARA autonomous submarine robot. Although this is the particular setting for which the system had been initially devised, thanks to its flexibility it can be easily configured to adjust to different contexts and situations, even if it is always based on the same simple basic visual mechanism. Keywords Visual plan, planning, plan specification, task specification.