[color=red]WITH TREE AS (
 SELECT PROZESS_CONFIG_ID , STATUS, START_DATE, END_DATE 
 FROM FUNKTION_STATUS
 ),
 TREE1 (PROZESS_CONFIG_ID,PARENT) AS (
 SELECT PROZESS_CONFIG_ID ,PARENT
 FROM DIM_PROZESS_CONFIG
 ),
 DATA AS (
 SELECT T1.*, T.STATUS, T.START_DATE, T.END_DATE
 FROM TREE1 T1
 LEFT JOIN TREE T ON T.PROZESS_CONFIG_ID = T1.PROZESS_CONFIG_ID
 ),
 DATA_WITH_LEAF AS (
 SELECT D.*, CONNECT_BY_ISLEAF IS_LEAF, ROWNUM RN, SYS_CONNECT_BY_PATH(PROZESS_CONFIG_ID, '/') PATH, LEVEL LVL
 FROM DATA D
 START WITH PARENT IS NULL
 CONNECT BY PARENT = PRIOR PROZESS_CONFIG_ID
 ),
 RES_TREE(PROZESS_CONFIG_ID, PARENT, STATUS, RN, START_DATE, END_DATE, PATH, LVL) AS (
 SELECT PROZESS_CONFIG_ID, PARENT, STATUS, RN, START_DATE, END_DATE, PATH, LVL
 FROM DATA_WITH_LEAF T
 WHERE IS_LEAF = 1
 UNION ALL
 SELECT D.PROZESS_CONFIG_ID, D.PARENT, CASE WHEN T.STATUS = 'FAILED' THEN T.STATUS ELSE NVL(D.STATUS, T.STATUS) END, D.RN, 
 NVL(D.START_DATE, T.START_DATE),
 NVL(D.END_DATE, T.END_DATE),
 D.PATH, D.LVL
 FROM DATA_WITH_LEAF D
 JOIN RES_TREE T ON T.PARENT = D.PROZESS_CONFIG_ID
 )
 SELECT PROZESS_CONFIG_ID, PARENT, MIN(STATUS) AS STATUS,
 MIN(TO_CHAR(START_DATE, 'DD-MM-YYYY HH24:MI:SS' )) AS START_DATE, MAX(TO_CHAR(END_DATE,'DD-MM-YYYY HH24:MI:SS')) AS END_DATE,
 PATH, LVL
 FROM RES_TREE
 GROUP BY PROZESS_CONFIG_ID, PARENT, RN, PATH, LVL
 ORDER BY RN
[/color]

  with tree as (
  select prozess_config_id , status, start_date, end_date
  from funktion_status
),
tree1    (prozess_config_id,parent) as (
  select prozess_config_id ,parent
  from dim_prozess_config
),
data as (
  select t1.*, t.status, t.start_date, t.end_date
  from tree1 t1
  left join tree t on t.prozess_config_id = t1.prozess_config_id
),
data_with_leaf as (
  select d.*, connect_by_isleaf is_leaf, rownum rn, sys_connect_by_path(prozess_config_id, '/') path, level lvl
  from data d
  start with parent is null
  connect by parent = prior prozess_config_id
),
res_tree(prozess_config_id, parent, status, rn, start_date, end_date, path, lvl) as (
  select prozess_config_id, parent, status, rn, start_date, end_date, path, lvl
  from data_with_leaf t
  where is_leaf = 1
  union all
  select d.prozess_config_id, d.parent, case when t.status = 'FAILED' then t.status else nvl(d.status, t.status) end, d.rn,
                nvl(d.start_date, t.start_date),
                nvl(d.end_date, t.end_date),
                d.path, d.lvl
  from data_with_leaf d
  join res_tree t on t.parent = d.prozess_config_id
),
res_group as (
  select prozess_config_id, parent,
                 min(status) as status, min(to_char(start_date, 'DD-MM-YYYY HH24:MI:SS' )) as start_date,
                 max(to_char(end_date,'DD-MM-YYYY HH24:MI:SS')) as end_date,
                 path, lvl
  from res_tree
  group by prozess_config_id, parent, rn, path, lvl
)
select *
from res_group
start with parent is null
connect by parent = prior prozess_config_id
order siblings by start_date, end_date
  

SQL> l
  1  with data as (select to_date('01-01-2016','dd-mm-yyyy') date1 from dual
  2                union all
  3                select to_date('04-01-2009','dd-mm-yyyy') date1 from dual)
  4* select max(to_char(data.date1,'dd-mm-yyyy')) from data
SQL> /

MAX(TO_CHAR(DATA.DATE1,'DD-MM-YYYY'))
---------------------------------------------------------------------------
04-01-2009