I sometimes use "as follows" as follows:
The system operates as follows. First, it receives data. Then, it processes the data. ...
That is, I sometimes uses "as follows" with a period not colon when a long explanation is needed after "as follows". But, as far as I know, using "as follows" with a period is incorrect, so I am looking for alternative expressions that can be used with a period. Is it correct to replace "as follows" with "as described below" as follows?:
The system operates as described below. First, it receives data. Then, it processes the data. ...