“are we supposed to know (for example) all kinds of inventory target , working capital, delivery performance etc formulas and calculate these (ball park) during the case study interview? If I have 2 - 3 days to brush up my tool-kit, how much depth of preparation would you recommend in this regard? Any specifics pls...”Oh dearWorrying question of the week.If you are interviewing for a Supply Chain experienced hire job, you should not need to “bone up” on these ratios. You should know them by rote, and be able to point to instances where you have used these tools. Still, EY aren’t too picky on who gets in, so I’m sure you’ll be able to bluff it. Most of the failed IBMers there seem to have made a career out of it.