1. Identify the three categories of models that are most critical for system preservation management. Discuss the importance of each category.
2. The condition of a certain engineering system ranges from 0 (failed) to 10 (excellent or as-new). The owner seeks the condition level at which rehabilitation of the system must be carried out. Explain why both liberal and conservative thresholds are not cost-effective and describe how you would establish the optimal threshold for that system.