Definition
The figure accumulated from the start of the fiscal year to the current month; bowling charts and metric boards mostly judge on the year-to-date number, because monthly attainment and year-to-date attainment often point in opposite directions.
In detail
Year to date and current month are two different rulers, and mixing them is one of the most common board errors. The three-colour rule of the bowling chart rests on exactly this distinction: green means year to date is on plan, yellow means year to date is on plan but the month missed, red means year to date missed. Yellow is the only cell in this colour set that admits a miss can still be caught up, so a two-colour chart makes losing one month look the same as losing eight. Before quoting any percentage, ask whether it is monthly or year to date, especially when year-over-year and month-over-month sit on the same sheet.
Example in practice
In a given month, a metric achieved only 92 percentage points, but Year to Date is still above plan, so the cell is marked yellow according to the rules and a Countermeasures sheet is required; after two consecutive months of yellow, Year to Date falls below plan, the cell turns red, and the Problem is escalated to the Tier 2 meeting.