Time Evaulation Schema TM04 (how linked with PY schema)

Dear friends ,

Could any one of you clearly tell me how the time schema are linked with py schema.

TM04 is the schema for time evaluation , how this particular schema is linked to the payroll schema.

1 more query is that how the negative time evaluation is done , where the modification must be i.e which schema and PCR is involved.

please reply friends as soon as possible

thanks & regards

sakthi