measuring growth in the number of orders, turnaround time, strategy for expanding
Basically all of the mentioned metrics can be converted into KPIs. The general logic to do this is to formulate a strategy first following the steps as explained in KPI system.
As for the “strategy for expanding” it is necessary to understand what this strategy will be, e.g. what are the main challenges, what are the obstacles, what is your proposed plan. Following this answers you will be able to find good performance metrics.