4-20. The theater army works closely with FORSCOM to match the composition of the force with the forces identified in theater security cooperation plans or contingency plans for a crisis. FORSCOM modifies force packages as needed. The theater army commander identifies the major task organization and predeployment training required for a mission. FORSCOM then modifies force packages and training as needed. Whenever possible, FORSCOM (or the supporting ASCC) attaches forces to its gaining higher headquarters during deployment (for example, attaching brigade combat teams [BCTs] to a different gaining division headquarters). If geography or the sequence of deployment makes this impractical, the theater army executes task organization changes when forces arrive in the AOR. The gaining theater army commander modifies administrative control (ADCON) as required based upon the organization of the JTF and the support structure available in the theater. Figure 4-2 illustrates force tailoring.