Sometimes an operation seems to call for a couple of plans linked together. A common scenario is a team that wants a two-pronged approach. "You create a diversion at the tavern, and when they send thugs over there, we'll break into their lair." There are two ways to handle this.

1. The diversion is a setup maneuver that a team member performs as part of the plan. A successful setup maneuver can improve position for teammates (possibly offsetting a bad engagement roll) or give increased effect. An unsuccessful setup maneuver might cause trouble for the second part of the plan—an easy consequence is to give the engagement roll -1d. If it makes sense, the team member who performed the setup can drift back into the main operation and join the team later so they don't have to sit out and wait.
2. The diversion is its own plan, engagement, and operation, whose outcome creates the opportunity for a future plan. Use this option when the first part of the plan is required for the next part to happen at all. For example, you might execute a stealth plan to steal an artifact from the Museum of the Ancients, then later use that artifact in an occult plan to consecrate a temple for your forgotten god. In this case, you go into downtime (and payoff, heat, etc.) after the first part of the plan, as normal.

Either approach is fine. It's usually a question of interest. Is the linked plan idea interesting enough on its own to play out moment by moment? Is it required for the second plan to make sense? If so, make it a separate operation. If not, just use a setup maneuver.