IntroductionSeveral works have show

Introduction

Several works have shown that maintenance is a strategic function, the impact of which influences almost all aspects of an organisation's performance, including competitiveness ([9] Madu, 2000), productivity ([12] Raouf, 1994), quality ([3] Ben-Daya and Duffuaa, 1995) and safety ([7] Holmgren, 2005). Thus, improving the effectiveness of maintenance is crucial. Several approaches have been proposed to evaluate maintenance performance in order to improve its effectiveness (see, for example, [5] De Groote, 1995; [11] Pintelon and Puyvelde, 1997; [6] Dwight, 1999; [14] Tsang, 1998; [15] Tsang et al. , 1999; [17] Yam et al. , 2000; [8] Kutucuoglu et al. , 2001). Yet, the impact of some of these approaches has been limited, because convincing top management of the necessity to implement these approaches in their organisations is not easy when the results expected from the improvement of the maintenance effectiveness, are not assessed in terms of financial profit. This evaluation is difficult to realize, furthermore, because of the time-lag effect characterizing the nature of maintenance, which is a support function of production ([11] Pintelon and Puyvelde, 1997). In addition to the constraint mentioned above, there is a lack of scientific work evaluating the contribution of maintenance to an organisation's profit creation (see, for example, [10] Oke, 2005).

To circumvent these problems, it is necessary to highlight the losses generated by the ineffectiveness of maintenance in order to convince top management to be involved in improving maintenance. Indeed, there are several situations where showing the negative effect of the absence of a concept is sufficient to show its importance. In medicine, for instance, it is diseases such as Beriberi which is caused by a lack of thiamine (vitamin B) and anemia, which is caused by an iron deficiency that proved the necessity of a balanced diet, which includes unrefined cereals, vegetables, meat, and milk. It follows that highlighting the impact of maintenance management ineffectiveness is a useful way to convince top management to take steps to correct it.

However, to be able to recommend necessary improvements to maintenance, it is not sufficient to demonstrate the negative impact of ineffective maintenance management on a company, but it is also essential to identify its causes. For this purpose, the audit approach is adopted. Despite the frequent use of this approach to identify insufficiencies and nonconformities in organisations, few results of maintenance system auditing have been published so far for reasons of confidentiality. The different steps to performing a maintenance audit are spelled out by [13] Raouf and Ben-Daya (1995) and [5] De Groote (1995). A concrete example of maintenance auditing, is provided by [1] Al-Muhaisen and Santarisi (2002). The principal component in the realization of an audit is the questionnaire. Questions must be developed for each significant factor, which affects the system under study ([13] Raouf and Ben-Daya, 1995). Although several factors are common to several firms, it is important to design the questionnaire such as to take into account the characteristics of each case ([13] Raouf and Ben-Daya, 1995).

The objective of our study is to evaluate the economic impact of maintenance management ineffectiveness and to identify the principal causes of its ineffectiveness using maintenance system auditing. For the economic impact section, we present the impact of maintenance management ineffectiveness on availability, maintenance cost, production cost, production revenue, natural resources and taxes. In the audit section, we take into account the characteristics of the case under study. Thus, maintenance system auditing is based on the factors identified by [4] Cholasuke et al. (2004) to which we added other factors that are important in the determination of maintenance effectiveness. Such an audit is useful for proposing a plan for maintenance improvement.

For confidentiality, we use initials instead of names. OG (oil group) stands for the Oil & Gas Group. The plant, the maintenance function of which we studied, is referred to by CS (case study).

The collection of information and data about the CS plant was made during the period from September 2006 to January 2007. The sources of collected information are:

- various reports from OG and CS (balance-sheets, meetings minutes, etc);

- interviews with managers, heads of departments, etc;

- use of an appropriate questionnaire; and

- on site observations.

In this paper, all the estimates are based on data from three years 2003, 2004 and 2005. However, the graphs take into account five years 2001, 2002, 2003, 2004 and 2005, in order to allow a better observation of the trends of the curves.

Maintenance context

CS is one of the most important plants of OG. The group OG employs 120,000 people and, in 2005, realized export sales turnover exceeding 45 billion US$ (American Dollars) and produced (all products taken together) 232 million TOE (tons oil equivalent). More than 10 per cent of this production volume came from CS. OG envisages increasing its production by more than 25 per cent by 2010. But, to achieve this goal, it is necessary to improve the availability of production equipment. Consequently, improving maintenance effectiveness is required. To highlight this need to the top management, we propose to evaluate the economic impact of maintenance dysfunctions within OG. We chose CS as a pilot case.

Several constraints characterize the current context of the maintenance function in CS. The most significant constraints are explained briefly below.

Interconnection and interdependence between the units

Figure 1 [Figure omitted. See Article Image.] provides an overall picture of the production process in CS. This figure shows the degree of interconnection and interdependence between the various phases of production. Thus, the output of one unit is often an input for another. Consequently, any stoppage of a unit will have an impact on the others. In addition, this figure shows that the gas produced along the production process, must be recovered to be injected into the oil wells, in order to maintain the pressure level in those wells. This recovery allows a better use of the gas resources and a minimization of the quantities of flared gas, which represents a threat to health as well as to the environment.

Large number of equipment

CS contains more than 46,000 components such as revolving machines (5,319), static equipment (1,679), electric equipment (4,627), instrumentation equipment (31,353), electronic equipment (3,771), etc. The strategic equipment of CS include 64 gas turbines, eight turbojets, 95 gas compressors, 36 electric motors and 12 high-pressure pumps.

Large number of manufacturers

The diversity of manufacturers is another significant constraint on maintenance in CS. There are, for example, a large number of manufacturers of turbines: General Electric, Hispano Suiza, Pratt/Whitney, Thomassen, Rolls-Royce, English Electric, Solar, Tornado and Worthington. The same is true of compressors; at least three companies produce them: Nuovo-pignone, Thermodyn and Dresser Rand.

Outdated equipment

The plant was built more than 50 years ago. Some manufacturers of the original factory equipment such as CEM for engines and Rateau for compressors are no longer in business.

Large number of spare parts

In CS, more than 120,000 items are in storage. Approximately 60,000 items are intended for maintenance applications.

The constraints listed above are likely to make the task of maintenance management in CS more difficult and to decrease its effectiveness. It is the responsibility of maintenance management to plan, supervise and improve the maintenance function in CS. The dysfunctions, which currently plague maintenance within CS, are signs of ineffectiveness of maintenance management that can be represented essentially through the indicators discussed below.

Cancellation of preventive maintenance programmes

In process industries where production generally operates continuously, the availability of equipment is very important ([2] Arts et al. , 1998). For this reason, elaborate maintenance programmes are often set up to ensure a high level of equipment availability and to avoid accidental stoppages, which cause significant financial losses.

The maintenance department of CS applies a systematic preventive maintenance in the form of periodic inspections according to an annual schedule. This schedule is based upon the accumulation of equipment operating time and the laws regarding equipment subjected to pressure (balloons, furnaces, aero-columns, storage tanks, etc). Curative maintenance is carried out after the occurrence of a sudden or progressive failure of equipment. The strategic equipment of CS includes turbines, compressors, electric motors and high-pressure pumps. The maintenance programme for turbines includes combustion inspection (CI) and major inspection (MI) performed after 12,000 and 48,000 operating hours respectively. For compressors the maintenance programme includes partial revision (PR) and general revision (GR) performed after 12,000 and 48,000 operating hours respectively. The engines (particularly the gas-powered generators) are sent to their manufacturers to be inspected and refurbished. A schedule for the inspection for gas pressured equipment (GPE) is also in place. The GPE revision programme is established in collaboration with the inspection department of the technical direction of CS, but is followed up by maintenance direction. Because maintenance tasks are numerous and varied, several activities are outsourced to more than 80 outside companies. The maintenance services outsourced include, for instance, the maintenance of power lines and some static equipment, boiler making, heat insulation, and the manufacture of mechanical equipment.

The

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PengenalanBeberapa karya telah menunjukkan bahwa pemeliharaan adalah fungsi strategis, dampak yang mempengaruhi hampir semua aspek kinerja organisasi, termasuk daya saing ([9] Madu, 2000), produktivitas ([12] Raouf, 1994), kualitas (Ben-Daya [3] dan Duffuaa, 1995) dan keselamatan ([7] Holmgren, 2005). Dengan demikian, meningkatkan efektivitas perawatan sangat penting. Beberapa pendekatan telah diusulkan untuk mengevaluasi kinerja pemeliharaan untuk meningkatkan efektivitas (Lihat, misalnya, [5] De Groote, 1995; [11] Pintelon dan Puyvelde, 1997; [6] Dwight, 1999; [14] Tsang, 1998; [15] Tsang et al., 1999; [17] yam et al., 2000; [8] Kutucuoglu et al., 2001). Namun, dampak dari beberapa pendekatan ini telah terbatas, karena meyakinkan top manajemen dari keharusan untuk menerapkan pendekatan ini dalam organisasi mereka tidak mudah ketika hasil yang diharapkan dari peningkatan efektivitas pemeliharaan, tidak dinilai dalam hal keuntungan finansial. Evaluasi ini sulit untuk menyadari, Selain itu, karena efek tenggang waktu mencirikan sifat pemeliharaan, yang merupakan dukungan fungsi produksi (Pintelon [11] dan Puyvelde, 1997). Selain kendala yang disebutkan di atas, ada kurangnya karya ilmiah yang mengevaluasi kontribusi pemeliharaan untuk sebuah organisasi keuntungan penciptaan (Lihat, misalnya, [10] Oke, 2005).To circumvent these problems, it is necessary to highlight the losses generated by the ineffectiveness of maintenance in order to convince top management to be involved in improving maintenance. Indeed, there are several situations where showing the negative effect of the absence of a concept is sufficient to show its importance. In medicine, for instance, it is diseases such as Beriberi which is caused by a lack of thiamine (vitamin B) and anemia, which is caused by an iron deficiency that proved the necessity of a balanced diet, which includes unrefined cereals, vegetables, meat, and milk. It follows that highlighting the impact of maintenance management ineffectiveness is a useful way to convince top management to take steps to correct it.However, to be able to recommend necessary improvements to maintenance, it is not sufficient to demonstrate the negative impact of ineffective maintenance management on a company, but it is also essential to identify its causes. For this purpose, the audit approach is adopted. Despite the frequent use of this approach to identify insufficiencies and nonconformities in organisations, few results of maintenance system auditing have been published so far for reasons of confidentiality. The different steps to performing a maintenance audit are spelled out by [13] Raouf and Ben-Daya (1995) and [5] De Groote (1995). A concrete example of maintenance auditing, is provided by [1] Al-Muhaisen and Santarisi (2002). The principal component in the realization of an audit is the questionnaire. Questions must be developed for each significant factor, which affects the system under study ([13] Raouf and Ben-Daya, 1995). Although several factors are common to several firms, it is important to design the questionnaire such as to take into account the characteristics of each case ([13] Raouf and Ben-Daya, 1995).Tujuan dari penelitian kami adalah untuk mengevaluasi dampak ekonomi ketidakefektifan manajemen pemeliharaan dan untuk mengidentifikasi penyebab utama ketidakefektifan yang menggunakan pemeliharaan sistem audit. Untuk bagian dampak ekonomi, kami hadir dampak ketidakefektifan manajemen pemeliharaan pada ketersediaan, biaya pemeliharaan, biaya produksi, pendapatan produksi, sumber daya alam dan pajak. Di bagian audit, kami mempertimbangkan karakteristik kasus diteliti. Dengan demikian, pemeliharaan sistem audit didasarkan pada faktor-faktor yang diidentifikasi oleh [4] Cholasuke et al. (2004) yang kami menambahkan faktor-faktor lain yang penting dalam penentuan efektivitas perawatan. Audit tersebut berguna untuk mengusulkan rencana untuk pemeliharaan perbaikan.Untuk kerahasiaan, kita menggunakan inisial bukan nama. OG (minyak group) singkatan dari minyak & Gas Group. Tanaman, fungsi pemeliharaan yang kita pelajari, disebut oleh CS (studi kasus).Pengumpulan informasi dan data tentang tanaman CS dibuat selama periode September 2006 untuk Januari 2007. Sumber-sumber informasi yang dikumpulkan adalah:-berbagai laporan dari OG dan CS (neraca, menit pertemuan, dll);-Wawancara dengan manajer, kepala departemen, dll;-menggunakan kuesioner yang tepat; dan-pada situs pengamatan.Dalam tulisan ini, semua perkiraan berdasarkan data dari tiga tahun 2003, 2004 dan 2005. Namun, grafik memperhitungkan lima tahun 2001, 2002, 2003, 2004 dan 2005, untuk memungkinkan pengamatan lebih baik dari tren kurva.Pemeliharaan konteksCS adalah salah satu tanaman terpenting OG. Group OG mempekerjakan 120.000 orang dan, pada tahun 2005, menyadari ekspor omset penjualan melebihi 45 miliar US$ (dolar Amerika) dan diproduksi (semua produk diambil bersama-sama) 232 juta TOE (setara ton minyak). Lebih dari 10 persen dari volume produksi ini datang dari CS. OG pemerintah meningkatkan produksi oleh lebih dari 25 persen pada tahun 2010. Namun, untuk mencapai tujuan ini, sangat penting untuk meningkatkan ketersediaan peralatan produksi. Akibatnya, meningkatkan efektivitas perawatan diperlukan. Untuk menyoroti kebutuhan untuk manajemen puncak, kami mengusulkan untuk mengevaluasi dampak ekonomi pemeliharaan disfungsi dalam OG. Kami memilih CS sebagai kasus pilot.Beberapa hambatan yang menjadi ciri khas konteks fungsi pemeliharaan CS. Kendala paling signifikan secara singkat dijelaskan di bawah.Interkoneksi dan saling ketergantungan antara unitFigure 1 [Figure omitted. See Article Image.] provides an overall picture of the production process in CS. This figure shows the degree of interconnection and interdependence between the various phases of production. Thus, the output of one unit is often an input for another. Consequently, any stoppage of a unit will have an impact on the others. In addition, this figure shows that the gas produced along the production process, must be recovered to be injected into the oil wells, in order to maintain the pressure level in those wells. This recovery allows a better use of the gas resources and a minimization of the quantities of flared gas, which represents a threat to health as well as to the environment.Large number of equipmentCS contains more than 46,000 components such as revolving machines (5,319), static equipment (1,679), electric equipment (4,627), instrumentation equipment (31,353), electronic equipment (3,771), etc. The strategic equipment of CS include 64 gas turbines, eight turbojets, 95 gas compressors, 36 electric motors and 12 high-pressure pumps.Large number of manufacturersThe diversity of manufacturers is another significant constraint on maintenance in CS. There are, for example, a large number of manufacturers of turbines: General Electric, Hispano Suiza, Pratt/Whitney, Thomassen, Rolls-Royce, English Electric, Solar, Tornado and Worthington. The same is true of compressors; at least three companies produce them: Nuovo-pignone, Thermodyn and Dresser Rand.Peralatan yang usangTanaman ini dibangun lebih dari 50 tahun yang lalu. Beberapa produsen asli pabrik peralatan seperti CEM untuk mesin dan Rateau kompresor yang tidak lagi dalam bisnis.Sejumlah besar suku cadangCS, lebih dari 120.000 item yang dalam penyimpanan. Kira-kira 60,000 item dimaksudkan untuk pemeliharaan aplikasi.Kendala-kendala yang tercantum di atas akan membuat tugas pemeliharaan manajemen di CS lebih sulit dan mengurangi efektivitas. Ini adalah tanggung jawab pemeliharaan manajemen untuk merencanakan, mengawasi dan meningkatkan fungsi pemeliharaan CS. Disfungsi, yang saat ini wabah maintenance dalam CS, merupakan tanda ketidakefektifan manajemen perawatan yang dapat diwakili pada dasarnya melalui indikator-indikator yang dibahas di bawah ini.Pembatalan program pemeliharaan preventifDalam proses industri mana produksi umumnya beroperasi secara terus-menerus, ketersediaan peralatan adalah sangat penting ([2] Arts et al. 1998). Untuk alasan ini, menguraikan pemeliharaan program sering dibentuk untuk memastikan tingkat tinggi ketersediaan peralatan dan menghindari penghentian disengaja, yang menyebabkan kerugian finansial.Departemen pemeliharaan CS berlaku pemeliharaan preventif sistematis dalam bentuk inspeksi periodik sesuai jadwal tahunan. Jadwal ini berdasarkan akumulasi peralatan waktu operasi dan undang-undang mengenai peralatan mengalami tekanan (balon, tungku, aero-kolom, tangki penyimpanan, dll). Kuratif pemeliharaan dilakukan setelah terjadinya tiba-tiba atau progresif kegagalan peralatan. Peralatan strategis CS termasuk turbin, kompresor, motor listrik dan pompa bertekanan tinggi. Program pemeliharaan turbin mencakup pemeriksaan pembakaran (CI) dan pemeriksaan utama (MI) dilakukan setelah 12.000 dan 48.000 jam operasi masing-masing. Untuk kompresor program pemeliharaan termasuk revisi parsial (PR) dan revisi Umum (GR) dilakukan setelah 12.000 dan 48.000 jam operasi masing-masing. Mesin (terutama bertenaga gas Generator) akan dikirim ke produsen mereka untuk diperiksa dan diperbaharui. Jadwal untuk inspeksi untuk peralatan gas ditekan (GPE) juga berada di tempat. Program revisi GPE didirikan bekerjasama dengan Departemen inspeksi arah teknis CS, tetapi diikuti oleh pemeliharaan arah. Karena tugas pemeliharaan banyak dan bervariasi, beberapa kegiatan outsourcing ke lebih dari 80 di luar perusahaan. Jasa pengurusan outsourcing mencakup, misalnya, pemeliharaan saluran listrik dan beberapa peralatan statis, membuat boiler, isolasi panas, dan pembuatan peralatan mekanis.The