## 4 Compilation of Failure Database and the Operations Administration of the Plant  
The ice cream manufacturing system functions on an 8 h shift per day, during the weekdays and including the weekends. During this time period, the production system functioned for a sum of 351 working days. Data from a 12-month period was collected by the technical department. The database is records of failures per work period which are kept by the technical department within each shift. Included in the database are the failures which have occurred per work period, the immediate actions needed by the maintenance staff to repair a failure, the exact time that the system not operate, and the accurate time of failure. Consequently, the accurate time when the equipment fails (or repairs) i.e., the accurate time-between-failure (TBF), and the time-to-repair (TTR) a failure can be attained. Both the TBFs and TTRs were registered within minutes. On the report of the records, a sum of 468 failures was established for the complete system. TBF of a system (or machine) is marked as the time which elapses once the system is turned on and begins functioning after a failure, up to the time it goes down anew and stops function because of a new failure. TTR of an unsuccessful system (or machine) is outlined as the time that elapses from the instant the system goes down and ceases until the instant it goes up again and starts functioning. The maintenance policy that is applied tothe ice cream production system is preventive, predictive, and corrective maintenance. Preventive maintenance is the scheduling of planned maintenance moves with the purpose of both the prevention of failures and breakdowns for the equipment. The main goal is the preservation and enhancement of the equipment's reliability, in order to increase its lifetime and help it runs more efficiently. The preventive maintenance is supported on an application of specific preventive moves for example greasing, belt-tightening, oil changes, changing filters, etc. The preventive maintenance program should be performed on equipment as recommended by the manufacturer i.e., time periods (daily, weekly, monthly, quarterly, etc). Predictive maintenance is considered as a technique that helps identify the condition of an in-service system (or machine) with an aim to determine when maintenance can be carried out. The objective of this maintenance is to minimize disruption of common system functions, however providing for scheduled repairs, budgeted. Predictive maintenance could be considered as the supplement of preventive maintenance. Using the utilization of numerous nondestructive testing and measuring methods (i.e., oil analysis, vibration analysis, infrared thermography, and visual inspections), predictive maintenance establishes the system (or machine) status prior to a failure occurring. Corrective maintenance is unprogrammed and executed whenever a breakdown happens. The process needs instant action of the technicians (i.e., mechanics and electricians) so as to return it to primary functioning condition. The benefit of the adequate maintenance policy is to increase equipment life by reducing failures and breakdowns. Moreover, this reduces costs that relate to the downtimes and decreases the cost of replacement. In Figure 2, the graphical summaries of TTRs and TBFs for the entire manufacturing system were shown. The graphical summaries include three graphs: (i) histogram of failure/repair database with an overlaid bell curve, (ii) boxplot, (iii) 95% confidence intervals for mean, median, and the standard deviation. The following observations were made: (a) Both TBFs and TTRs have the \(p\)-value \(\leq\) 0.005, the failure database do not accompany a Gaussian distribution. (b) With a confidence interval of 95%, the meanTBF measurement is between 310.80 and 357.52 min. Whereas the meanTTR measurement is between 23.148 to 27.095 min. (c) The boxplots show the variability, shape, and central tendency of the failure database.