A dotted line on an org chart is a promise that somebody's work is directed by two people, and most charts make that promise without saying what it covers. The person under it then discovers the boundary the hard way, usually in a week when both managers want something on Thursday. This page is what a dotted line should mean on your chart, written so it can go in the key, plus the count nobody runs: on the worked example a 140-person company carries 43 dotted lines against 140 solid ones, which is 183 reporting relationships and about 46 hours a month of standing check-ins.
What the dashes should mean, written down
A dotted line directs work; a solid line writes the review, approves the leave and decides the priority when the two conflict. Put that sentence in the chart's key and half the confusion disappears, because the ambiguity in most matrix companies is not who the second manager is, it is what the second manager may ask for. A chart that carries the rule teaches every new joiner in five seconds what otherwise takes them a quarter.
When a dotted line is the right answer
When somebody's work is genuinely directed by two people and neither line can be removed: a designer embedded in a product team, an analyst serving three departments, a regional manager with a functional boss. When it is used instead to show that two people talk often, it is decoration, and decoration on a chart is what teaches people to stop reading it.
What the second line costs, counted
43 dotted lines with a fortnightly thirty-minute check-in is 46 hours a month of manager time, about $2,428 at a $52 hourly cost and $29,149 a year. Spread over 18 managers that is 2.4 extra reports each on top of a team of seven. Neither figure argues against the matrix; both make the third dotted line a decision rather than a drift.
Questions people ask about dotted line org chart
Can somebody have two dotted lines?
Yes, and the worked example assumes an average of 1.4. Past two the person is effectively unmanaged, because nobody has enough of their week to notice how it is going.
Do dotted lines belong in the directory or just the chart?
In the directory. The chart is a view; if the relationship only exists in the drawing it disappears the next time the chart is regenerated.
How do we show a temporary project line?
As a dotted line with an end date on the record. The end date is what stops a project structure from quietly becoming the permanent one.