Translation:The board of directors progresses step by step.
Now, here's a question and I'm not sure there is any definitive correct answer.
Should it be ŝtupo or paŝo?
I guess I've always imagined the steps invoked by the phrase step by step to be those the steps taken when walking, not the steps taken when going up steps. So if I had had a situation where I went to translate the phrase, I would have chosen paŝon post paŝo.
Very good question! I looked it up and learned something.
Progresi in intransitive, has no direct object (I wondered and controlled it).
The "ŝtupon post ŝtupo " = "[per] ŝtupo post ŝtupo" is a unity, describing the progress. Search Google for the similar case "paŝon post paŝo".
THE grammar http://bertilow.com/pmeg/gramatiko/rolmontriloj/rolvortetoj/rolvortetforlaso.html says that both "ŝtupo post ŝtupo" (old) and "ŝtupon post ŝtupo" (new) are possible and fine.