Getting Login timeout error in executing load Plan

Hello Team,

I am getting below error in executing the load plan.and this error does come randomly not regularly like once a week.

select CASE WHEN 'Global Variable Refresh' in (select distinct group_code from C_PARAMETER_VALUE_FORMATTER_V where PARAM_CODE= 'DIAG_HEALTHCHECK_RUN_FLAG')

THEN (select param_value

from C_PARAMETER_VALUE_FORMATTER_V

where PARAM_CODE=  'DIAG_HEALTHCHECK_RUN_FLAG'

and group_code='Global Variable Refresh'

and datasource_num_id = '#BIAPPS.WH_DATASOURCE_NUM_ID')

ELSE

(select param_value from C_GL_PARAM_VALUE_FORMATTER_V where PARAM_CODE=  'DIAG_HEALTHCHECK_RUN_FLAG' and datasource_num_id = '#BIAPPS.WH_DATASOURCE_NUM_ID')