Invalid materialized view

Hi team,

In our 12.1.0.2 database I have 3 materialized views which are in invalid state. I have checked with this query and it seems that they are unusable:

SELECT MVIEW_NAME,  UNUSABLE, KNOWN_STALE, INVALID 
FROM DBA_MVIEW_ANALYSIS 
WHERE OWNER = 'APPS' 
AND INVALID = 'Y';

also have checked last DDL:

select object_name,last_ddl_time,status from dba_objects where object_name in ('AS_SUBORDINATE_REPS_MV','AS_GROUP_MV','LNS_LOAN_DTLS_ALL_MV');

As i have read from several sources DML on underlaying MV tables can invalidate MV itself. So my thoughts to compile or refresh those views.