 The time and effort required depends on the configuration of the ACBM, the number and type of CBM components to be removed, and on the interfaces to be connected between the two elements.It may be budgeted for as much as ten hours although, in at least some cases, that time might be paused to conduct an extended "fine leak check" by before opening the hatch into the vestibule.Because they overlap the crew corridor through the vestibule, the CPAs must always be cleared away, and it is always necessary to remove any covers across the hatch on the newly berthed element.