1. there are four types in general principle of maintenance concept. list down and give brief explanations of each types of maintenance concept.

Four types of maintenance concept are corrective, preventive, risk- based and condition- based maintenance.

Explanation:

In corrective maintenance repair activities are carried out when a fault or slight defect is detected. This carried out by considering that the cost of repair will be lower than the expenses incurred when continuous maintenance approach is chosen.

In preventive maintenance approach , maintenance is carried out in definite intervals so as to reduced the risk of failure.

Risk based maintenance is carried out by integrating appropriate analysis and periodic test activities to the preventive maintenance approach. In condition bases maintenance the equipment performance is monitored and the corrective actions are controlled.

answer; i believe the correct answer is norming;