# Service Life Prediction and Life Cycle Costs of Light Weight Partitions
## 4 Field Survey Results and Discussion
### Service Life Expectancy and Performance Level under Failure Conditions  
Assuming that each failure factor operates independently from others, the cumulative and partial influence on a partition's weighted standard deterioration path (initial state and standard failure) can be quantified by using the following expression:  
\[TWCP=-\alpha*age+\beta-\left[\frac{100-ICP}{n}\right]-\sum_{1}^{m}\left[\frac{100 -FCP_{m}}{n}\right] \tag{6}\]  
where:  
\(TWCP\) -Weighted performance under failure conditions (initial state + standard failure + specific failure). \(\alpha\), \(\beta\) -Regression parameters of the typical deterioration path in standard conditions. \(ICP\) -Average Initial Component Performance. \(FCP_{m}\) -Average component performance of a specific failure mechanism. \(n\) -Number of component deterioration characteristics in standard conditions  
\(m\) -Number of independent failure mechanisms  
This expression, which is used to predict the comprehensive service life expectancy of partitions in various scenarios, considers each failure factor, both independently and in combination (Figure 14). The summarized results are presented in Tables 7-9. Figure 14: Comparative Service Life Prediction of Building Partitionsin Various Occupancy Conditions. Each chart corresponds to a specific failure mechanism. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Gypsum Board** & \multicolumn{1}{c}{**Light**} & **Moderate** & **Standard** & **Intensive** \\ \hline
**Occupancy Conditions** & \multicolumn{1}{c}{\(\mu\) = 0} & \multicolumn{1}{c}{\(1\leq\mu\) < 2} & \multicolumn{1}{c}{\(2\leq\mu\) < 4} & \multicolumn{1}{c}{\(\mu\geq\) 4} \\ \hline
**Failure mechanism** & \multicolumn{4}{c}{**Crack at Partition-Ceiling Junction**} \\ \hline Service life prediction MRCP60\% [years] & 76 & 37 & 20 & 8 \\ Expected service life interval MRCP60\% [years] & 70–82 & 33–41 & 18–23 & 3–13 \\ Component performance interval expected at 20 years & 82–86 & 70–77 & 57–64 & 10–39 \\ Component performance interval expected at 25 years & 80–84 & 66–73 & 50–57 & 0–25 \\
**Failure mechanism** & \multicolumn{4}{c}{**Crack at Partition-Wall Junction**} \\ \hline Service life prediction MRCP60\% [years] & 79 & 39 & 21 & 8 \\ Expected service life interval MRCP60\% [years] & 73–85 & 35–43 & 19–24 & 4–13 \\ Component performance interval expected at 20 years & 83–87 & 71–79 & 58–65 & 11–40 \\ Component performance interval expected at 25 years & 81–85 & 68–74 & 52–59 & 0–26 \\
**Failure mechanism** & \multicolumn{4}{c}{**Crack Around Door Frame**} \\ \hline Service life prediction MRCP60\% [years] & 78 & 38 & 21 & 8 \\ Expected service life interval MRCP60\% [years] & 73–84 & 34–42 & 19–24 & 3–13 \\ Component performance interval expected at 20 years & 83–87 & 71–78 & 58–65 & 11–40 \\ Component performance interval expected at 25 years & 81–85 & 67–74 & 51–58 & 0–26 \\
**Failure mechanism** & \multicolumn{4}{c}{**Cracks on the Surface**} \\ \hline Service life prediction MRCP60\% [years] & 79 & 39 & 21 & 8 \\ Expected service life interval MRCP60\% [years] & 73–85 & 35–43 & 19–24 & 4–13 \\ Component performance interval expected at 20 years & 83–87 & 71–79 & 58–65 & 11–40 \\ Component performance interval expected at 25 years & 81–85 & 68–74 & 52–59 & 0–26 \\
**Failure mechanism** & \multicolumn{4}{c}{**Stability of Electrical Installations**} \\ \hline Service life prediction MRCP60\% [years] & 78 & 38 & 21 & 8 \\ Expected service life interval MRCP60\% [years] & 72–84 & 34–42 & 18–24 & 3–13 \\ Component performance interval expected at 20 years & 83–87 & 71–78 & 58–65 & 10–40 \\ Component performance interval expected at 25 years & 80–85 & 67–74 & 51–58 & 0–25 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Service Life Predictions at a Minimum Required Component Performance level of 60% (MRCP60%); Component Performance Intervals for Gypsum Board in Different Occupancy Conditions.