LINE

line. Needs: ordered periods + 2 to 4 numeric series.

trendchange-over-time

DL-01 AGRAW

Use when

trend over ordered periods
plan vs actual tracking
2 to 4 series maximum

Do not use when

categorical comparison (use CH-RNK-01 or CH-MAG-01)
cumulative progress vs plan (use CH-TIM-02 S-CURVE)
more than 4 series (use small multiples)
unordered categories

See instead

values are cumulative progress vs plan: CH-TIM-02
comparison across categories: CH-RNK-01

Alternatives

CH-TIM-03 (area, planned)
CH-TIM-05 (slope, planned)
CH-TIM-06 (sparkline, planned)

Rules

y starts at zero; a non-zero baseline needs a written justification in the entry that uses it
series labeled at line ends, never a legend
exactly one key series; the rest are context
horizontal gridlines only
annotation points at the data, with a leader line

Never do this

legend boxes
more than one saturated series
dual y axes
markers on every point
smoothed or spline-interpolated lines

QA before delivering

no legend anywhere
series labels at line ends
gridlines horizontal only
y axis starts at zero or the justification is recorded
annotation present and anchored to a data point
title states a finding with a number
source line present bottom-left

Data shape

title	string, action title stating the finding with a number
eyebrow	string caps, rendered only when the DL chrome asks for it
source	string, rendered bottom-left, always
unit	string, appears once, on the top y tick label
x	array of ordered period labels
series	array of {name: string, values: number[] same length as x, role: 'key'\|'context'}, exactly one key
annotation	{text: string, series: name, index: int, tx: px, ty: px, anchor: 'start'\|'end'}, points at a data point

Sample data (golden)

{
  "title": "Actual progress reached 62% in June, 9 points behind plan",
  "eyebrow": "PROGRESS . H1 2026",
  "source": "Source: sample dataset v1, 2026-07-12",
  "unit": "%",
  "x": [
    "Jan",
    "Feb",
    "Mar",
    "Apr",
    "May",
    "Jun"
  ],
  "series": [
    {
      "name": "Plan",
      "values": [
        10,
        25,
        40,
        52,
        63,
        71
      ],
      "role": "context"
    },
    {
      "name": "Actual",
      "values": [
        8,
        20,
        33,
        45,
        55,
        62
      ],
      "role": "key"
    }
  ],
  "annotation": {
    "text": "gap widens from April",
    "series": "Actual",
    "index": 3,
    "tx": 470,
    "ty": 340,
    "anchor": "end"
  }
}