En supposant SQL Server, voici un exemple :
DECLARE @T table (id int, [month] char(3), flag bit)
INSERT INTO @T
VALUES
(111, 'jan', 1)
,(111, 'feb', 1)
,(111, 'mar', 1)
,(111, 'apr', 0)
,(111, 'may', 0)
,(111, 'jun', 1)
,(222, 'jan', 1)
,(222, 'feb', 1)
,(222, 'mar', 0)
,(222, 'apr', 0)
,(222, 'may', 0)
,(222, 'jun', 1)
SELECT
id
, [month]
, flag
, ROW_NUMBER() OVER (PARTITION BY id, section ORDER BY monthNum) [order]
FROM
(
SELECT
id
, [month]
, monthNum
, flag
, SUM(CASE WHEN newValue = 1 THEN 1 ELSE 0 END) OVER (PARTITION BY id ORDER BY monthNum) section
FROM
(
SELECT
id
, [month]
, monthNum
, flag
, CASE WHEN LAG(flag, 1, ABS(flag - 1)) OVER (PARTITION BY id ORDER BY monthNum) = flag THEN 0 ELSE 1 END newValue
FROM
(
SELECT
id
, [month]
, MONTH(CAST('1 ' + [month] + ' 17' AS datetime)) monthNum
, flag
FROM @T
) Q
) Q2
) Q3
