A security team that ignores its alerts is usually described as a discipline problem. It is almost never a discipline problem. It is a system producing more alerts than any human could triage, and humans responding rationally by filtering the whole channel out. The fix is not exhortation. It is fewer, better alerts.
The number that matters is alerts per analyst per shift
Not detection coverage. Not rules deployed. Alerts a human is expected to actually look at during one shift, and whether that number is compatible with looking at them properly.
If an analyst faces hundreds of alerts in a shift, they are not triaging, they are pattern-matching for the ones that look interesting, which is exactly the behaviour an attacker relies on. A tuned system produces a volume a person can genuinely work through, and every one of them deserves the attention.
Vendor content is a starting point, never a deployment
Every SIEM ships with rule packs. They are written for a generic environment that does not exist, and deployed unmodified they generate enormous noise: your backup job looks like mass file access, your vulnerability scanner looks like an attacker, your admin's legitimate 2am maintenance looks like off-hours privilege use.
Those are not false positives in the strict sense. The rule fired correctly. It fired on your normal, because nobody told it what your normal is. Tuning is largely the work of teaching the system what routine looks like here.
Start from use cases, not from log sources
The common failure sequence: buy the SIEM, connect every log source available, enable the default rules, drown. Ingestion becomes the goal and detection never arrives.
Invert it. Decide what you need to detect based on what would actually hurt this business. Ransomware staging. Credential theft leading to email fraud. An insider exporting the customer database. For each, work out which log sources are required, and connect those. Some sources will not be ready, and documenting that gap honestly is more useful than claiming coverage you do not have.
An alert needs to arrive with its context
An alert reading "suspicious login detected" costs an analyst ten minutes of pivoting between consoles before they can judge it. Multiply by the shift volume and that is the whole shift.
Enrich at detection time. Who is this account, and is it privileged? Is this device managed? Has this address been seen before? Is this user usually active at this hour? The alert should contain enough for a triage decision without leaving the screen. This is the single highest-return improvement available in most SOCs, and it is engineering work, not analyst work.
Correlation is the point
One failed login is nothing. One failed login on fifty accounts from one address is password spraying. A successful login from a new country, followed by a mailbox rule creation, followed by a bulk download, is an account takeover in progress, and each event alone is unremarkable.
Rules that fire on single events produce noise. Rules that fire on sequences produce signal. Writing the second kind requires understanding attack progression, which is why generic content cannot do it for you.
Tuning never finishes, and that is fine
Environments change. New applications appear, staff patterns shift, attack techniques evolve. A rule tuned perfectly in January is producing noise by June because the business changed underneath it.
Budget for tuning as an ongoing activity with a named owner, not as a phase at the end of the implementation project. The alternative is what we usually find when we are called into an existing deployment: a system that was accurate once, drifted, and lost its audience. We treat this as the core of SIEM work, and reviewing an existing deployment's alert volume is often more valuable than adding a single new rule.