Diesel engine is widely use for different applications, the failure frequency of diesel engine is more increase to increase the age & use of engine in order to take decision to replacement of engine on the basis of Repair & Maintenance cost (R&M) & predication of future Repair & Maintenance costs of diesel engine used in Borewell compressor. Present case study discusses prediction of accumulated R&M costs (Y) of Diesel engine against usage in hours (X). Recorded data from the company service station is used to determine regression models for predicting total R&M costs based on total usage hours. The statistical results of the study indicates that in order to predict total R&M costs is more useful for replacement decisions than annual charge.

1. International Journal of Recent advances in Mechanical Engineering (IJMECH) Vol.3, No.1, February 2014
63
PREDICTION OF REPAIR & MAINTENANCE
COSTS OF DIESEL ENGINE
D.R.Dolas1
, M.D. Jaybhaye2
, Sudhir. D. Deshmukh3
1, 3
Department of Mechanical Engineering, MGM’s Jawaharlal Nehru Engineering
College, Aurangabad, Maharashtra – 431003, India.
2
Department of Production Engineering, College of Engineering Pune, Pune,
Maharashtra - 411005, India.
ABSTRACT
Diesel engine is widely use for different applications, the failure frequency of diesel engine is more
increase to increase the age & use of engine in order to take decision to replacement of engine on the basis
of Repair & Maintenance cost (R&M) & predication of future Repair & Maintenance costs of diesel engine
used in Borewell compressor. Present case study discusses prediction of accumulated R&M costs (Y) of
Diesel engine against usage in hours (X). Recorded data from the company service station is used to
determine regression models for predicting total R&M costs based on total usage hours. The statistical
results of the study indicates that in order to predict total R&M costs is more useful for replacement
decisions than annual charge.
KEYWORDS
Diesel Engine, R & M Cost, Maintenance, Regression Model, Age replacement model.
1. INTRODUCTION
Diesel engine is one of the most important power sources in different applications. Effect of
diesel engine power on Borewell compressor is considerable. The use of Borewell compressor for
making tube wells during latter decades resulted in rapid growth of farm & requirement drinking
water.
Costs of owning and operating including the preventive & corrective maintenance cost of diesel
engine is very important for deciding the appropriate time to replace the diesel engine on basis of
repair & maintenance cost. The new engine failure are occurring rarely therefore less
maintenance cost, but age increase the maintenance cost is increase.
G.M. Khoub et al. [1] presented the repair & maintenance cost model on the basis of mean
working hours & mean accumulated cost of MF285 tractor. To predicate repair & maintenance
cost the power model most suitable. Development of model for predication Repair & maintenance
cost for two wheel drive tractor & suggested strongly the polynomial model by Ranjba et al. [2].
Khodabakhshian R. & Shakeri M carried out the statistical analysis of different farm tractors on
the basis of repair & maintenance cost & total working hour using Preventive Maintenance [3].
Donca Gh. [4] mean accumulated maintenance cost of U683dt tractor analysis using different
model & recommended power model best model for predication the maintenance cost. The study
was conducted by Shahram et.al. [5] For JD-4955 tractors showed that the polynomial regression
model strongly recommended in order to predict accumulated R&M costs. R. Ahmad [6]
proposed a maintenance management decision model for preventive maintenance application &
determines the revised PM interval for machine. Fereydoun proposed model provides for the

2. International Journal of Recent advances in Mechanical Engineering (IJMECH) Vol.3, No.1, February 2014
64
Prediction of repair and maintenance costs of Massey Ferguson 285 (MF-650) tractors &
suggested polynomial regression model [7]. Artificial neural network technique is used for
predication of repair & maintenance cost & recommended this is best tool. [8]. Isaac & et al. [9]
presented the cubic polynomial least square regression cost prediction. Sebo et al. [10] determine
optimum replacement model for replacement machine using least squares method. Y. H. Chien &
J. A. Chen [11] uses of age replacement model determine the average cost per unit time. K. Yao
& D. A. Ralescu [12] provide the age replacement policy involving random age has been
proposed & assumed the age of the unit is an uncertain. Shey Huei Sheu1 & Chin-Chih Chang
[13] using the age replacement models determine optimal age for preventive replacement cost can
be minimized.
The aim of this study is to provide a statistical analysis for the repair and maintenance costs of
diesel engine of application for Borewell compressor in order to present an appropriate
mathematical model implementation of appropriate models for the repair and maintenance costs
of diesel engine provide planner and policy makers and also owner an opportunity to evaluate
performance of diesel engine economic.
2. DATA COLLECTION
This study is carried out at authorized service station. Failure & maintenance cost data is
collected & sorted from forty same make & model diesel engine. Corrective & preventive
maintenance cost estimated using age replacement model.
3. DETERMINATION OF COST PER HOUR USING AGE
REPLACEMENT MODEL
To determine the repair & maintenance cost per hour using Age replacement model
CሺTሻ =
Cf Fሺtሻ + Cp Rሺtሻ
‫׬‬ ܴሺ‫ݐ‬ሻ݀‫ݐ‬
௧
଴
− − − −ሺ1ሻ
Age replacement model is more useful in practical application for the determine of Repair &
maintenance cost (preventive & corrective ) & estimate maintenance cost per hour. To determine
the cost function C (T). Using Weibull distribution model [6] is shown in equation. (2)
CሺTሻ =
Cf ሺ1 – ݁
ିቀ
௧
ఎ
ቁ
ഁ
+ Cpሺ ݁
ିቀ
௧
ఎ
ቁ
ഁ
‫׬‬ ܴ ݁
ିቀ
௧
ఎ
ቁ
ഁ
݀‫ݐ‬
௧
଴
− − − − − − − ሺ2ሻ
Where:
Cf - Failure cost Cp - Preventive replacement cost Cs – cost of spare parts
F (t) = Cumulative distribution function R (t) = Reliability function
FሺTሻ = 1 − ݁
ିቀ
೟
ആ
ቁ
ഁ
RሺTሻ = e
ିቀ
౪
η
ቁ
β
FሺTሻ + RሺTሻ = 1
η – Scale parameters (characteristic life), β- Shape parameters (variation of the failure rate)
Failure cost & preventive replacement costs can be determine using following equations
C୤ = C୰ + Cୢ & Cp = C୧ + Cୢ
Where:
Cf - Failure cost Cp - Preventive replacement cost
Cr - Cost of replacement system & components
Cd - Cost of down time Ci - Cost preventive servicing
Cost of down time = one hour cost = 90 (ft) × 60 (Rs) = 5400× Failure / hour

3. International Journal of Recent advances in Mechanical Engineering (IJMECH) Vol.3, No.1, February 2014
65
Estimation of reliability of diesel engine using Weibull distribution using failure data &
maintenance cost per hour.
The system probability of failure function = FሺTሻ = 1 − ݁
ିቀ
೟
ആ
ቁ
ഁ
− − − − − ሺ3ሻ
The system reliability function = RሺTሻ = e
ିቀ
౪
η
ቁ
β
− − − − − −ሺ4ሻ
FሺTሻ + RሺTሻ = 1 − − − − − ሺ5ሻ
t = 3000 hours, β = 2.198 & η = 1929.46
F(t) =1 -݁
ିቀ
మలమఴ
భవమవ.రల
ቁ
మ.భవఴ
= 1 -݁ିሺଵ.ଷ଺ଶ଴ሻమ.భవఴ
= 1 - ݁ି ଵ.ଽ଻
= 1- 0.14= 0.86
R(t) = 1-F(t) = 1-0.86 = 0.14
Table 1. Estimation of average cost per hour

4. International Journal of Recent advances in Mechanical Engineering (IJMECH) Vol.3, No.1, February 2014
66
4. PREDICATION MODEL DEVELOPMENT:
To estimate the appropriate repair & maintenance cost model for diesel engine using different
regression models, as per different researchers presented & suggested the regression model for
farm tractors are [2], [3], [4].
Y = a + bx Linear
Y = a + bx + cxଶ
Polynomial
Y = a + lnbx Logarithmic
Y = aeୠ୶
Exponential
Y = axୠ
Power
Fig. 1 Regression models of maintenance cost of diesel engine

5. International Journal of Recent advances in Mechanical Engineering (IJMECH) Vol.3, No.1, February 2014
67
Development of appropriate mathematical model for predicting repair and maintenance
costs for diesel engine, using repair & maintenance cost of forty diesel engines Table 1.
The presented data in this Table 1 is used to analysis and determine the predicated repair
and maintenance cost per hour as shown in Table 2.
Table.2 Repair & Maintenance Cost per Hour
Fig. 2 Maintenance cost Predication Regressions model of diesel engine
y = 0.004x + 71.78
R² = 0.635
y = 61.81e4E-05x
R² = 0.472
y = 32.15ln(x) - 145.4
R² = 0.678
y = -1E-07x2 + 0.008x + 61.88
R² = 0.676
y = 5.551x0.348
R² = 0.693
-100
0
100
200
300
400
0 10000 20000 30000 40000 50000
Cost/Hours
Time
C(T)
Linear
(C(T))
Expon
.
(C(T))
Log.
(C(T))
Poly.
(C(T))
Power
(C(T))

6. International Journal of Recent advances in Mechanical Engineering (IJMECH) Vol.3, No.1, February 2014
68
Table.3 Regression models
Regression Models R2
Linear Y = a + bx 0.635
Polynomial Y = a + bx + cxଶ 0.676
Exponential Y = aeୠ୶ 0.472
Logarithmic Y = a + lnbx 0.678
Power Y = axୠ 0.693
5. RESULT & DISCUSSION
Table 3 presents regression models for predication the repair and maintenance cost per hour of
diesel engines. The Power model correlation coefficient is highest value(0.693) compared to
other models. Therefore recommended that the Power model best model for Borewell compressor
diesel engine
In the most of researchers published studies in this field of Farm equipment, machinery & tractors
suggested the Power model gave better cost prediction with higher confidence and less variation
than that of Exponential and logarithmic models. Because of, easiness in calculations, the small
difference between the correlation coefficients of Polynomial and Power models and using of
Power model by other researchers, As per Table3 other models are less significant.
6. CONCLUSION
The Repair & Maintenance costs prediction of Borewell compressor diesel engine & deciding the
time to replacement. The repair coefficients values are generally dependent on factors such as
research method performance and time spans, number and type of samples. Results of this study
indicated that the Repair & Maintenance costs per hour increased with engine age. This resulted
in a marginally increased total repair cost curve. These results also confirmed that there are
considerable variations in Repair & Maintenance costs among engine models as well as
individual ones. For circumstances similar to this study, estimates suggest that annual R&M costs
increase with age of engine. This method is more useful for replacement decisions than annual
charge.
ACKNOWLEDGEMENT
The authors are deeply grateful for help and guidance rendered by General Manager Mr. Yuvraj
Lavhale and employees of Trinity Mahalasa Durga sales & services, Aurangabad during field
studies.

7. International Journal of Recent advances in Mechanical Engineering (IJMECH) Vol.3, No.1, February 2014
69
REFERENCES
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Environ. Sci., 4 (1): pp 76-80,
[2] Iraj Ranjba , Majid rashidi, Borzoo Gharee I Khabba,( 2010), “Prediction of repair and maintenance
costs of two-wheel Drive tractors in iran,” XVII th World Congress of the International Commission
of Agricultural and Biosystems Engineering (CIGR) pp 1-10
[3] Khodabakhshian R.& Shakeri M.,( 2011), “ Prediction of repair and maintenance costs of farm
tractors by using of preventive maintenance ,” International Journal of Agriculture Sciences, Vol. 3,
Issue 1, pp-39-44
[4] Donca Gh.,( 2011 )“Maintenance cost model for U683DT Tractor, “ Analele Universita Nii din
Oradea , Fascicula: Ecotoxicologie, Zootehnie i Tehnologii de Industrie Alimentara, pp 131-136
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Authors
Shri. Dolas Dhananjay R , BE (Mech) & ME- Mechanical (Design Engineering) working
as a Associate Professor in Mechanical engineering at MGM’S Jawaharlal Nehru College
of Engineering , Aurangabad . He has 6 publications in National/International conferences
& Journals & Pursuing PhD
Dr.Maheshwar D Jaybhaye, Ph.D (Mech.Prod.Engg.) Working as AssociateProfessoer,
Production Engineering Department at College of Engineering, Pune. He has 16
publications in National/International conferences & Journals. He is life member of ISTE,
Tribology Society India, Operation Research Society of India & Associate Member of
Associate Member Institution of Engineers (India). He is recipient of K.F.Antia memorial
Award (Gold Medal) from Institution of Engineers (India).
Dr. Sudhir D Deshmukh , Ph.D (Mechanical Engg.) working as Principal MGM’s
Jawaharlal Nehru College of Engineering, College, Aurangabad. He has more than 25
publications in his credit in National/International conferences &Journals. He is life member
of ISTE and Fellow Member of Institution of Engineers (India), Fellow of Institution of
Production Engineers, Chartered Engineer & Chairman, Quality Circle Forum of India
(QCFI), Aurangabad.