SQL Server 2017

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CREATE TABLE Table1
    ([customer_id] int, [mis_date] datetime, [status] int, [group] varchar(4))
;
    
INSERT INTO Table1
    ([customer_id], [mis_date], [status])
VALUES
    (10003, '2014-01-01 00:00:00', 1),
    (10003, '2014-01-02 00:00:00', 1),
    (10003, '2014-01-03 00:00:00', 0),
    (10003, '2014-01-04 00:00:00', 0),
    (10003, '2014-01-05 00:00:00', 0),
    (10003, '2014-01-06 00:00:00', 1),
    (10003, '2014-01-07 00:00:00', 1),
    (10003, '2014-01-08 00:00:00', 1),
    (10003, '2014-01-09 00:00:00', 1),
    (10003, '2014-01-10 00:00:00', 0),
    (10003, '2014-01-11 00:00:00', 0),
    (10003, '2014-01-12 00:00:00', 0),
    (10003, '2014-01-13 00:00:00', 1),
    (10003, '2014-01-14 00:00:00', 1),
    (10003, '2014-01-15 00:00:00', 1)
;
15 rows affected

 select [customer_id], [mis_date], [status],
    COALESCE(LAG(status) over (order by mis_date), status) oldstatus
  FRom Table1


customer_id
mis_date
status
oldstatus


10003
01/01/2014 00:00:00
1
1

10003
02/01/2014 00:00:00
1
1

10003
03/01/2014 00:00:00
0
1

10003
04/01/2014 00:00:00
0
0

10003
05/01/2014 00:00:00
0
0

10003
06/01/2014 00:00:00
1
0

10003
07/01/2014 00:00:00
1
1

10003
08/01/2014 00:00:00
1
1

10003
09/01/2014 00:00:00
1
1

10003
10/01/2014 00:00:00
0
1

10003
11/01/2014 00:00:00
0
0

10003
12/01/2014 00:00:00
0
0

10003
13/01/2014 00:00:00
1
0

10003
14/01/2014 00:00:00
1
1

10003
15/01/2014 00:00:00
1
1


with cte0 as 
( 
  select [customer_id], [mis_date], [status],
    COALESCE(LAG(status) over (order by mis_date), status) oldstatus
  FRom Table1
),
cte1 as ( 
  select cte0.*, 
    case when status = 0 then 
      null 
    else
      COUNT( case when  status != oldStatus and status = 0 then 1  else null end) OVER (ORDER BY mis_date) 
    end + 1 grp
  from cte0
)
select * from cte1


customer_id
mis_date
status
oldstatus
grp


10003
01/01/2014 00:00:00
1
1
1

10003
02/01/2014 00:00:00
1
1
1

10003
03/01/2014 00:00:00
0
1
null

10003
04/01/2014 00:00:00
0
0
null

10003
05/01/2014 00:00:00
0
0
null

10003
06/01/2014 00:00:00
1
0
2

10003
07/01/2014 00:00:00
1
1
2

10003
08/01/2014 00:00:00
1
1
2

10003
09/01/2014 00:00:00
1
1
2

10003
10/01/2014 00:00:00
0
1
null

10003
11/01/2014 00:00:00
0
0
null

10003
12/01/2014 00:00:00
0
0
null

10003
13/01/2014 00:00:00
1
0
3

10003
14/01/2014 00:00:00
1
1
3

10003
15/01/2014 00:00:00
1
1
3


Warning: Null value is eliminated by an aggregate or other SET operation.

customer_id	mis_date	status	oldstatus
10003	01/01/2014 00:00:00	1	1
10003	02/01/2014 00:00:00	1	1
10003	03/01/2014 00:00:00	0	1
10003	04/01/2014 00:00:00	0	0
10003	05/01/2014 00:00:00	0	0
10003	06/01/2014 00:00:00	1	0
10003	07/01/2014 00:00:00	1	1
10003	08/01/2014 00:00:00	1	1
10003	09/01/2014 00:00:00	1	1
10003	10/01/2014 00:00:00	0	1
10003	11/01/2014 00:00:00	0	0
10003	12/01/2014 00:00:00	0	0
10003	13/01/2014 00:00:00	1	0
10003	14/01/2014 00:00:00	1	1
10003	15/01/2014 00:00:00	1	1