In the case of SSB, David is responsible for maintaining a sufficient quantity of materials in inventory. Recall that in the manual environment David must rely on physical observations that the quantity of materials in the warehouse is getting low. With an ES, however, David can simply retrieve an inventory report from the system to determine if a requisition is necessary (see area 1 in Figure 3.8). Moreover, as Figure 3.8 illustrates, the ES also provides David with other data he will need, such as vendors and purchasing history.