Explanation
It is recommended to enable Detect-Only for Troubleshooting on the profile during the initial installation of IPS.
This option overrides any protections that are set to Prevent so that they will not block any traffic.
During this time you can analyze the alerts that IPS generates to see how IPS will handle network traffic, while avoiding any impact on the flow of traffic.

Explanation
Suspicious Activity Rules Solution
Suspicious Activity Rules is a utility integrated into SmartView Monitor that is used to modify access privileges upon detection of any suspicious network activity (for example, several attempts to gain unauthorized access).
The detection of suspicious activity is based on the creation of Suspicious Activity rules. Suspicious Activity rules are Firewall rules that enable the system administrator to instantly block suspicious connections that are not restricted by the currently enforced security policy. These rules, once set (usually with an expiration date), can be applied immediately without the need to perform an Install Policy operation References:

Explanation/Reference:
Reference: https://sc1.checkpoint.com/documents/R76/
CP_R76_PerformanceTuning_WebAdmin/6731.htm