with increasing demand (and therefore increasing capacity requirements) from period $t$ to $t+1$ receive capacity module(s) from the depot of from locations that have decreasing capacity requirements (e.g. lower left unit zone in Figure \[fig: Relocation\]).

The relocation of capacity modules over the network adjusts the storage capacity available in each access hub for the following period. In this study, we assume capacity module relocation is performed by a separate business unit whose routing decisions are out of the scope of the research reported in this paper.\
The objective is to minimize the cost incurred by operating such a network of access hubs without disrupting underlying operations. The decision scope is tactical (capacity deployment) and requires the integration of operational decisions. However, since the main interest is a set of tactical decisions, there is no need to explicitly model operations, but only to approximate the impact of deployment decisions on routing cost and time synchronization.\
Let $L$ be a set of access hub locations and $W$ a set of external depots composing a network $G=(N=L\cup W,A)$ where $A$ is the complete set of directed arcs between locations in $N$. A capacity deployment of $I_0$ capacity modules in time $t$ over 