/case/ - Case Studies

i am currently putting together a few new case studies for my agency website. i wanna move away from just listing what we did and focus more on the actual impact our work had on their operations. it is difficult to explain the value of long term strategy w/o making it sound like fluff. i struggle w/ how to present the transition from the initial problem to the final outcome without being too wordy.
structure ideas
does anyone have a template for presenting results? i want to highlight the before and after states clearly. specifically, i am trying to figure out if it is better to lead with the success story or start with the client struggle. i think leading with the win is boring .
>the problem was a lack of clear process
i also wonder if including raw data or just high level summaries works better for potential clients reading this. i do not want to reveal sensitive info but i need to show that our methods work. any advice on how to keep these readable but professional would be great.