Hi,
If preventive maintenance is active ,then pick the task list for the equipment.and If preventive maintenance is not active,then follow the steps
1.Create task for the equipement in IA01/IA05 with control key PM03(external service)refer screenshot
2.create maintenance :Create activity type in in kl01and assign price in kp26(secondery cost element),and create service number in ac01
3.create maintenanace plan in ip41and schedule it in ip10.
4.Check the same mantenance plan in ip24 and click on order where you can see actual cost through serive number posting and plan cost through activity type 