(I edited the answer for the sake of clarity)
Re-reading your question, it seems you are more after a way to classify messages in categories like Status, Warning and Error. To me those cannot be classified automatically, because knowledge of the business case is necessary to do so. You can maintain a matrix of classification that you will enrich over time.
I add below some information about Event Management and Incident Management, which are part of ITIL, and could be of some use for your particular case.
Priority is usually considered as a function of impact and urgency.
Information, warning and exceptions are levels of information, generated by events.
ITIL has a matrix that describes priority depending on impact/urgency.
ITIL suggests that priority be made dependent on Impact and Urgency.
Out-of-box, this is true on incident forms. Priority is generated from
Urgency and Impact according to the following table:
Urgency 1 Urgency 2 Urgency 3
Impact 1 Priority 1 Priority 2 Priority 3
Impact 2 Priority 2 Priority 3 Priority 4
Impact 3 Priority 3 Priority 4 Priority 5
I am adding more information, from the comments i've received it's not clear for everyone how you get the urgency and the impact in the first place.
What is important to note is that the classification of impact/urgency depends of your organization and business case.
Urgency categorization example
High (H) The damage caused by the Incident increases rapidly.
Work that cannot be completed by staff is highly time sensitive.
A minor Incident can be prevented from becoming a major Incident by acting immediately.
Several users with VIP status are affected.
Medium (M) The damage caused by the Incident increases considerably over time.
A single user with VIP status is affected.
Low (L) The damage caused by the Incident only marginally increases over time.
Work that cannot be completed by staff is not time sensitive.
Considering the different event types, ITIL describes 3 categories: Information, Warning, and Exception.
Informational events are typically events within normal operating
boundaries. They are the types of “good” events that tend to fill most
IT Service Management tools. These events are typically an indication
that something has worked as it should.
Warnings are an early indicator or potential indicator of trouble.
However, we need to understand that a warning is a flag to something
being “unusual”, not necessarily negative (e.g. someone logs in after
6 weeks of inactivity)
Exceptions are the most typical precursor to incidents, but they will
not always lead to an incident (e.g. a CPU spikes above the set
threshold as a power user starts a processing job). Exception events
will generally be of interest to IT Operations staff as they may be a
sign of more trouble to come.
One thing to note is that event management and incident management are linked, but not completely. You can have incidents (so impact/urgency giving you a priority) without having an event of the form information/warning/exception (for example if a user calls to say something is not working, compared to when your monitoring would throw an exception because a service is down).