SBLHow to plan answers in the SBL exam

Should we prepare the answer plan for all the requirement/parts at once in the beginning of answer booklet??(ie one answer plan for entire paper at one place in the beginning)And then begin writing in detail for each part?? Or answer plan just before answering each requirement separately.(ie answer plan for each requirement(ie if there r 4 questions..4 answer plan spread across the answer booklet )???