Create PercentileMetrics.js

Author: franks883

Core ServiceNow APIs/GlideAggregate/Incident resolution percentile by assignment group/PercentileMetrics.js

@@ -0,0 +1,82 @@
+// Script Include: PercentileMetrics
+// Purpose: Compute percentile resolution times by group using nearest-rank selection.
+// Scope: global or scoped. Client callable false.
+
+var PercentileMetrics = Class.create();
+PercentileMetrics.prototype = {
+  initialize: function() {},
+
+  /**
+   * Compute percentiles for incident resolution times by group.
+   * @param {Object} options
+   *   - windowDays {Number} lookback window (default 30)
+   *   - groupField {String} field to group by (default 'assignment_group')
+   *   - percentiles {Array<Number>} e.g. [0.5, 0.9]
+   *   - table {String} table name (default 'incident')
+   * @returns {Array<Object>} [{ group: <sys_id>, count: N, avgMins: X, p: { '0.5': v, '0.9': v } }]
+   */
+  resolutionPercentiles: function(options) {
+    var opts = options || {};
+    var table = opts.table || 'incident';
+    var groupField = opts.groupField || 'assignment_group';
+    var windowDays = Number(opts.windowDays || 30);
+    var pct = Array.isArray(opts.percentiles) && opts.percentiles.length ? opts.percentiles : [0.5, 0.9];
+
+    // Build date cutoff for resolved incidents
+    var cutoff = new GlideDateTime();
+    cutoff.addDaysUTC(-windowDays);
+
+    // First pass: find candidate groups with counts and avg
+    var ga = new GlideAggregate(table);
+    ga.addQuery('resolved_at', '>=', cutoff);
+    ga.addQuery('state', '>=', 6); // resolved/closed states
+    ga.addAggregate('COUNT');
+    ga.addAggregate('AVG', 'calendar_duration'); // average of resolution duration
+    ga.groupBy(groupField);
+    ga.query();
+
+    var results = [];
+    while (ga.next()) {
+      var groupId = ga.getValue(groupField);
+      var count = parseInt(ga.getAggregate('COUNT'), 10) || 0;
+      if (!groupId || count === 0) continue;
+
+      // Second pass: ordered sample to pick percentile ranks
+      var ordered = new GlideRecord(table);
+      ordered.addQuery('resolved_at', '>=', cutoff);
+      ordered.addQuery('state', '>=', '6');
+      ordered.addQuery(groupField, groupId);
+      ordered.addNotNullQuery('closed_at');
+      // Approx resolution minutes using dateDiff: closed_at - opened_at in minutes
+      ordered.addQuery('opened_at', 'ISNOTEMPTY');
+      ordered.addQuery('closed_at', 'ISNOTEMPTY');
+      ordered.orderBy('closed_at'); // for stability
+      ordered.query();
+
+      var durations = [];
+      while (ordered.next()) {
+        var opened = String(ordered.getValue('opened_at'));
+        var closed = String(ordered.getValue('closed_at'));
+        var mins = gs.dateDiff(opened, closed, true) / 60; // seconds -> minutes
+        durations.push(mins);
+      }
+      durations.sort(function(a, b) { return a - b; });
+
+      var pvals = {};
+      pct.forEach(function(p) {
+        var rank = Math.max(1, Math.ceil(p * durations.length)); // nearest-rank
+        pvals[String(p)] = durations.length ? Math.round(durations[rank - 1]) : 0;
+      });
+
+      results.push({
+        group: groupId,
+        count: count,
+        avgMins: Math.round(parseFloat(ga.getAggregate('AVG', 'calendar_duration')) / 60),
+        p: pvals
+      });
+    }
+    return results;
+  },
+
+  type: 'PercentileMetrics'
+};