Booking Travel Services
Use
Once you have chosen the required travel services you can book all the chosen items from a travel plan online via the connected reservation system.
Depending on the process model the booking can either be carried out decentralized by the traveler or the area secretary, or they can be carried out centrally by a travel agency or the internal travel center.
Note that the means of transport and accommodations selected in the travel plan can only be definitely booked for a certain time period. If, for example, only a limited number of seats are available for a flight this can not be guaranteed over a long period of time.
Activities
To book the requests from a travel plan in the Planning Manager together, choose 
Book with quick info Book Travel Plan (Ctrl + F11).
A corresponding posting key (PNR) is created that can be uniquely identified by the connected reservation system and that can also be modified at a later date.
In Customizing you can specify that all the bookings made by a connected travel agency are to be automatically put in a processing queue for the ticket issue. In this case you do not need to request the ticket manually using the corresponding pushbutton. You make these settings in the Customizing for Travel Management, under Travel Planning ® Master Data ® Control Parameters for Travel Planning ®
Define Queues for PNR Resubmission.