In this single iteration, the crew's start time is 247 days. However, during pre-construction planning, one can only estimate this start date. Given the uncertainty in getting matching spools to site, it may make sense to build in a time buffer or lag preceding the Install activity to enable the crew to be optimally productive once they mobilize (e.g., start Install no earlier than day 250). Buffering protects the installation crew from upstream process uncertainties and buys time for them to plan and get ready, or do other work in the mean time.