Re: what are all the things to be considered to write a effective perl script or module?

[ww]

Though dHarry's and Bloodnok's replies imply something that's often said here, let me take a stab at making "step one" explicit:

FIRST, use your native tongue to ( explain to yourself | write down ) each step you'd need to take ( "how you'd do it with pencil and paper | a calculator | manually" ) to achieve the result you want and what your $data looks like.

and SECOND, check for modules that may already exist to satisfy your requirements.