Conducting map scans is crucial as the first step because it allows the analyst to identify and understand the network topology and detect all devices connected to the network. Knowing the network layout and devices present ensures that no asset is missed during the vulnerability scan. Other options do not directly contribute to discovering all assets on the network. Scheduling is about planning when to execute scans and does not help in discovering assets. Understanding regulatory requirements is necessary to ensure compliance but is not the first step in discovering network assets. Lastly, deploying intrusion prevention systems is a security measure that does not contribute to the discovery of network assets.