Development of a Downtime Influence Factor Severity Index for ,mprovement of Naval Ship Availability A 6imple $pproach for the Malaysian Patrol Vessel In-Service Support Contract Al-Shafiq Abdul Wahid, Mohd Zamani Ahmad, Sunarsih, Nur Hanani Ahmad Azlan, Arifah Ali Faculty of Mechanical Engineering, Universiti Teknology Malaysia (UTM), 81310 Skudai, Malaysia, al_shafiq@hotmail.com Mohd Najib Abdul Ghani Yolhamid, Mohamad Abu Ubaidah Amir Abu Zarim Faculty of Science and Defence Technology, Universiti Pertahanan Nasional Malaysia, Kem Sungai Besi, 57100, Malaysia najib@upnm.com.my, amir.a@upnm.edu.my Aisha Abdullah Enigma Technical Solutions Sdn Bhd, Desa Villas, Section 10, Wangsa Maju, 53300 Kuala Lumpur, Malaysia Abstract— Navies worldwide have applied with a varied degree of success various maintenance concepts to achieve certain targeted operational ship availability. Nevertheless, few concepts focus on both the human and equipment factors that drive the unavailability or downtime. These factors can be designated as Downtime Influence Factors (DIFs). In previous research the severe DIFs had been identified via a 5-Stage Delphi conducted with experts in the field of Patrol Vessel (PV) In-Service Support (ISS) Contracts in Malaysia. By prioritizing and rating these DIFs based on Risk Assessment it was possible to determine a Severity Index formula. In a first step, the Severity Index (SI) prioritized the DIFs that are severe. In a subsequent step, the interrelationship of the DIFs was analyzed with the help of SPSS and the SI index was adjusted to take into account interrelationships. The resulting adjusted SI assists PV ISS contract stakeholders to pinpoint and focus on human and equipment factors that are the main causes of downtime. Index Terms—Naval Ship Availability, Downtime Influence Factors (DIFs), Severity Index (SI) I. INTRODUCTION Since the 1980’s there have been efforts in studying availability improvement concepts to military assets [1]. Various maintenance concepts had been applied by diverse industries worldwide ever since with different degrees of success. The operational availability of warships and the requirements to improve ship availability has been rejuvenated as of late as studied by Dell'Isola and Vendittelli, 2015 [2], especially due to, firstly, the criticality of achieving the balance between availability and life cycle cost (LCC) of warships and, secondly, focusing on proper design process, methods, models and tools to help achieve this. Further recent studies in operational availability improvement of Naval Vessels for the Royal Netherlands Navy pointed out that the operational availability was below the requirements [3]. The most important factor highlighted by Dell'Isola and Vendittelli (2015) [2] was the fact that an ‘availability-based’ contract needs to be formulated and long enough to ensure return on investment for the contractor. This is true for the European Multi-Mission Frigates (FREMM) of the French and Italian Navies and also to some countries like UK and Australia that have moved towards ‘availability-based’ contracting. However, this is not the case for the many navies globally which adhere to their traditional contracts in maintaining their naval vessels in accordance with their existing policies. The Royal Malaysian Navy (RMN) to date remains with the existing conventional policy of ‘per-repair’ contracts similar to most navies around the world including US Navy. Similar with other assets, a naval ship or platform requires day-to-day operations and maintenances. However, its complexity is higher than other assets due to their floating and movable condition. Furthermore, they have cross-functional capability to meet different roles and missions depending on time and conditions and political scenarios. Unlike other assets, the complexity increases rapidly as the naval ships are expected to be able to change its roles and missions in an extremely short turn-around-time depending on situations. Blanchard and Fabrycky, 1998 [4] and Inozu, 1996 [5] defined availability is as the probability that the ship is available and capable of performing the intended function at any random point in time. Availability which is also commonly known as ‘Uptime’ can be formulated as one minus downtime as stated in Hou Na et al., 2012 [6] or known as unavailability, with the resulting mathematically implication that the more the unavailability or ‘downtime’, the lesser the availability yielded. Ship operational availability is also described as the number of days the warships are available for operational tasking in a year (US Government Accountability Office, 2015) [7]. 2017 7th IEEE International Conference on Control System, Computing and Engineering (ICCSCE 2017), 24–26 November 2017, Penang, Malaysia 978-1-5386-3897-2/17/$31.00 ©2017 IEEE 305