comparison of various techniques for software effort ... · comparison of various techniques for...
TRANSCRIPT
International Journal On Advanced Computer Theory And Engineering (IJACTE)
________________________________________________________________________________________________
________________________________________________________________________________________________
ISSN (Print): 2319-2526, Volume -4, Issue -4, 2015
1
Comparison of various Techniques for Software Effort Estimation
1RshmaChawla,
2Deepak Ahlawat
1,2 MMICTBM, MMU Mullana
Email: [email protected],
Abstract: The most significant activity in software project
management is Software development effort prediction.
Software development effort estimation is the process of
predicting the most realistic use of effort required for
developing software based on some parameters. Software
effort estimation at early stages of project development
holds great significance for the industry to meet the
competitive demands of today’s market. In this paper,
software development effort estimation using Fuzzy
Triangular Membership Function, GBell Membership
Function, Gauss2 Membership Function and Trapezoidal
Membership Function is implemented using Mamdani
Type Fuzzy inference system of Fuzzy Logic Toolbox
Software of Matlab 7.5 and the results of these
membership functions are compared with each other and
with COCOMO model. It is found that the Fuzzy Logic
Model using Trapezoidal Membership Functionprovided
best results. However, if transition between the phases is
smoothly desirable, then Gauss2 Membership Function
gives better result then GBell Membership Function. The
criterion chosen for comparing the results is Mean
Magnitude of Relative Error (MMRE).
Keywords:Software Effort Estimation, Fuzzy Logic,
COCOMO Model, Membership Functions, NASA63
dataset.
I. INTRODUCTION
Software development is the computer programming,
documenting, testing, and bug fixing involved in
creating and maintaining applications and frameworks
involved in a software release life cycle and resulting in
a software product.
1.1. Software Development EffortEstimation
Software effort estimation is the prediction of the likely
amount of cost, time, and staffing levels required to
build a software system at an early stage during a
project. It is difficult to obtain the effort estimate during
the preliminary stages, because of the limited resources
available at that time [7].
1.2. Need for Effort Estimation
1. It would facilitate increased control of time and
overall cost benefit in software development life cycle.
2. Software development effort estimates are the
basis for project bidding and planning.
3. Software effort estimation has even been
identified as one of the three most demanding challenges
in software application areas. During the development
process, the cost and time estimates are useful for the
initial rough validation and monitoring of the project’s
completion process. And in addition, these estimates
may be useful for project productivity assessment
phases.
1.3. Size Estimation
The estimation of size is very critical and difficult area
of project planning. It has been recognized a crucial step
from the very beginning. Metric used for size estimation
is the Source Lines of Code.A line of code is any line of
program text that is not a comment or a blank line,
regardless of the number of statements or fragment of
statements on the line. This specially includes all lines
containing program header, declarations, and executable
and non-executable statements.Unit of measurement is
KLOC (Kilo lines of code).
There are several cost, schedule, and effort estimation
models which use LOC as an input parameter, including
the widely-used Constructive Cost Model (COCOMO)
invented by Barry Boehm [7].
1.4. COCOMO Model
The Constructive Cost Model (COCOMO) is an
algorithmic software cost estimation model
developed by Barry W. Boehm.
COCOMO was first published in Boehm’s 1981
book Software Engineering Economics as a
model for estimating effort, cost, and schedule
for software projects. COCOMO is a model that
allows one to estimate the cost, effort, and
schedule when planning a new software
development activity.
This model estimates the total effort in terms of
“person – months” of the technical project staff.
COCOMO is a hierarchy of software cost
estimation models, which include basic,
intermediate and detailed sub models.
Boehm proposed 3 modes of projects:
International Journal On Advanced Computer Theory And Engineering (IJACTE)
________________________________________________________________________________________________
________________________________________________________________________________________________
ISSN (Print): 2319-2526, Volume -4, Issue -4, 2015
2
1. Organic mode – simple projects that engage small
teams working in known and stable environments.
2. Semi-detached mode– projects that engage teams with
a mixture of experience. It is in between organic and
embedded modes.
3. Embedded mode– complex projects that are
developed under tight constraints with changing
requirements.
1.4.1. Intermediate COCOMO Model
The basic model initially developed by Barry Boehm
allowed for a quick and rough estimate, but it resulted in
a lack of accuracy. So Boehm introduced (reduced large
number of candidate factors down to relatively
manageable number of factors which can be used for
practical software cost estimation) resulting set of 15
factors (predictors), or cost driver attributes. This model
is referred as Intermediate COCOMO Model or
COCOMO II.
The cost drivers are grouped into following four
categories [7, 23]
1. Product attributes
(a) Required software reliability (RELY)
(b) Database size (DATA)
(c) Product complexity (CPLX)
2. Computer attributes
(a) Execution time constraints (TIME)
(b) Main storage constraints ( STOR)
(c) Virtual Machine volatility (VIRT)
(d) Computer Turnaround time (TURN)
3. Personal Attributes
(a) Analyst capability (ACAP)
(b) Application experience (AEXP)
(c) Programmer capability (PCAP)
(d) Virtual machine experience (VEXP)
(e) Programming language experience (LEXP)
4. Project attributes
(a) Modern programming practices (MODP)
(b) Use of software tools (TOOL)
(c) Required development schedule (SCED)
Each of these cost driver attributes determines a
multiplying factor which estimates the effect of the
attribute on software development effort. These
multipliers are applied to nominal COCOMO
development effort estimate to obtain a refined estimate
of software development effort [23].
Table 1.1: Intermediate COCOMO nominal effort
estimating equations
Development Mode Nominal Effort Equation, Ei
Organic
Semi-Detached
Embedded
(MM)NOM = 3.2(KDSI)1.05
(MM)NOM = 3.0(KDSI)1.12
(MM)NOM = 2.8(KDSI)1.20
Table 1.2:Effort multipliers for different cost drivers
S. No Cost Driver Symbol Very Low Low Nominal High Very High Extra High
1 RELY 0.75 0.88 1.00 1.15 1.40 -
2 DATA - 0.94 1.00 1.08 1.16 -
3 CPLX 0.70 0.85 1.00 1.15 1.30 1.65
4 TIME - - 1.00 1.11 1.30 1.66
5 STOR - - 1.00 1.06 1.21 1.56
6 VIRT - 0.87 1.00 1.15 1.30 -
7 TURN - 0.87 1.00 1.07 1.15 -
8 ACAP - 0.87 1.00 1.07 1.15 -
9 AEXP 1.29 1.13 1.00 0.91 0.82 -
10 PCAP 1.42 1.17 1.00 0.86 0.70 -
11 VEXP 1.21 1.10 1.00 0.90 - -
12 LEXP 1.14 1.07 1.00 0.95 - -
13 MODP 1.24 1.10 1.00 0.91 0.82 -
14 TOOL 1.24 1.10 1.00 0.91 0.83 -
15 SCED 1.23 1.08 1.00 1.04 1.10 -
The multiplying factors for all 15 cost drivers are
multiplied to get the effort adjustment factor (EAF). The
final effort estimate, E, is obtained by multiplying the
initial estimate by the EAF.
That is,
Development Effort = EAF * Ei ....(1)
1.5. Fuzzy Logic Approach
Since fuzzy logic foundation by LotfiZadeh in 1965, it
has been the subject of important investigations [15, 16].
It is a mathematical tool for dealing with uncertainty and
also it provides a technique to deal with imprecision and
information granularity. The fuzzy logic model uses the
fuzzy logic concepts introduced by LotfiZadeh. Fuzzy
reasoning consists of three main components:
International Journal On Advanced Computer Theory And Engineering (IJACTE)
________________________________________________________________________________________________
________________________________________________________________________________________________
ISSN (Print): 2319-2526, Volume -4, Issue -4, 2015
3
fuzzification process, inference from fuzzy rules and
defuzzification process. Fuzzification process is where
the objective term is transformed into a fuzzy concept.
The membership functions are applied to the actual
values of variables to determine the confidence factor or
membership function (MF). Fuzzification allows the
input and output to be expressed in linguistic terms.
Inferencing involves defuzzification of the conditions of
the rules and propagation of the confidence factors of
the conditions to the conclusion of the rules. A number
of rules will be fired and the inference engine assigned
the particular outcome with the maximum membership
value from all the fired rules.
1.6. Parameters Analysis
The main parameter for the evaluation of cost estimation
models is the Magnitude of Relative Error (MRE) which
is defined as follows
Magnitude Relative Error (RE) = ˆE E
E
Where E = Estimated Effort, E =Actual Effort.
The MRE value is calculated for each observation i
whose effort is predicted. The aggregation of MRE over
multiple observations (N) can be achieved through the
Mean MRE (MMRE) as follows:
………………… (2)
Lower value of MMRE is better [24].
II. FUZZY IDENTIFICATION
A fuzzy model [6] is used when the systems are
notsuitable for analysis by conventional approach or
when theavailable data is uncertain, inaccurate or vague
[15, 17]. The pointof Fuzzy logic is to map an input
space to an output spaceusing a list of if-then statements
called rules. All rules areevaluated in parallel, and the
order of the rules is unimportant.For writing the rules,
the inputs and outputs of the system areto be identified.
To obtain a fuzzy model from the dataavailable, the
steps to be followed are:
1. Select a Mamdani type Fuzzy Inference system.
2. Define the input variables mode, size and output
variableeffort.
3. Set the type of the membership functions (TMF
orGBellMF orGauss2 or Trapezoidal).
4. Write the appropriate fuzzy rules in Rule editor.
5. Select the Rule viewer and calculate the estimated
fuzzy effort.
The framework is shown in “Fig. 2.1”.
Figure 2.1: Fuzzy Framework for Effort Estimation
MODE
Estimated
SIZE Effort
Fuzzy Rules
In FIS, first gives the range of MODE of the project for
particular Membership Function then gives the range for
the SIZE. The range of Development Effort is the Actual
Effort given in the NASA63 dataset.
2.1. Fuzzy Rules
Our rules [24] are based on the fuzzy sets of MODE,
SIZE and EFFORT appears in the following form:
If MODE is Organic and SIZE is S1 then EFFORT is
EF1
If MODE is Semidetached and SIZE is S1 then
EFFORT is EF2
If MODE is Embedded and SIZE is S1 then EFFORT is
EF3
If MODE is Organic and SIZE is S2 then EFFORT is
EF4
If MODE is Semidetached and SIZE is S2 then
EFFORT is EF5
If MODE is Embedded and SIZE is S3 then EFFORT is
EF5
If MODE is Embedded and SIZE is S4 then EFFORT is
EF3
If MODE is Organic and SIZE is S3 then EFFORT is
EF4
If MODE is Embedded and SIZE is S5 then EFFORT is
EF6
If MODE is Organic and SIZE is S4 then EFFORT is
EF4
---------------------------------------------------
This is represented in MATLAB as shown in figure
below:
Figure 2.2: Fuzzy Rules
FIS
International Journal On Advanced Computer Theory And Engineering (IJACTE)
________________________________________________________________________________________________
________________________________________________________________________________________________
ISSN (Print): 2319-2526, Volume -4, Issue -4, 2015
4
2.2.Membership Functions
A membership function (MF) is a curve that defines how
each point in the input space is mapped to a membership
value (or degree of membership) between 0 and 1. The
input space is sometimes referred to as the universe of
discourse, a fancy name for a simple concept.One of the
most commonly used examples of a fuzzy set is the set
of tall people. In this case the universe of discourse is all
potential heights, say from 3 feet to 9 feet, and the word
tall would correspond to a curve that defines the degree
to which any person is tall. If the set of tall people is
given the well-defined (crisp) boundary of a classical
set, we might say all people taller than 6 feet are
officially considered tall. But such a distinction is
clearly absurd. It may make sense to consider the set of
all real numbers greater than 6 because numbers belong
on an abstract plane, but when we want to talk about real
people, it is unreasonable to call one person short and
another one tall when they differ in height by the width
of a hair [31].
2.2.1. Fuzzy Logic Membership Functions used in
this Research
1. Trimf - Triangular-shaped built-in membership
function
Syntax: y = trimf(x, params)
y = trimf(x,[a b c])
Description: The triangular curve is a function of a
vector, x, and depends on three scalar parameters a, b,
and c, as given by
f (x;a,b,c) = max( min( , …… (3)
2.Gbellmf-Generalized bell-shaped built-in membership
function
Syntax:y = gbellmf(x,params)
Description:The generalized bell function depends on
three parameters a, b, and c as given by
f(x;a,b,c) = ……(4)
Where the parameter b is usually positive. The
parameter c locates the center of the curve. Enter the
parameter vector params, the second argument for
gbellmf, as the vector whose entries are a, b, and c,
respectively.
3. Trapmf-Trapezoidal-shaped built-in
membership function
Syntax: y = trapm f(x, [a b c d])
Description: The trapezoidal curve is a function of a
vector, x, and depends on four scalar parameters a, b, c,
and d, as given by
f(x;a,b,c,d)=max(min( ),0)………………(5)
The parameters aandd locate the “feet” of the trapezoid
and the parameters b and c locate the “shoulders.”
4. Gauss2mf - Two-sided Gaussian membership
function.
Syntax:y = gauss2mf(x,[sig1 c1 sig2 c2])
Description:TheGaussianfunctiondependsontwoparame
terssigandcasgivenby
f (x;σ,c) = ……….(6)
The function gauss2mf is a combination of two of the
setwoparameters. The first function,
specifiedbysig1andc1, determines the shape of the left-
mostcurve.
Thesecondfunctionspecifiedbysig2andc2determines the
shape of the right-most curve. Whenever c1 < c2,
thegauss2mf functionreachesamaximumvalueof1.
Otherwise,themaximumvalue islessthanone.
III. EXPERIMENTAL RESULTS
Experiments were done by taking original datafrom
NASA63 dataset [7]. The softwaredevelopment efforts
obtained when usingCOCOMO and other membership
functions wereobserved.
Figure 3.1: Output of the results in MATLAB
International Journal On Advanced Computer Theory And Engineering (IJACTE)
________________________________________________________________________________________________
________________________________________________________________________________________________
ISSN (Print): 2319-2526, Volume -4, Issue -4, 2015
5
Table 3.1:Developmental Effort Estimate using various Techniques
S.
No
Project
id
MODE SIZE EAF Actual
Effort
Int.
COCOMO
Est. Effort
Est.
Effort
using
Trap
MF
Est.
Effort
using
TMF
Est.
Effort
using
GBell
MF
Est.
Effort
using
Gauss2
MF
1 1 1.2 E 113 2.72 2040 2215.24 1920 1910 1790 1800
2 4 1.05 O 46 1.17 240 208.56 226 225 211 212
3 7 1.05 O 6.9 0.40 8 9.72 7.54 7.49 7.02 7.06
4 10 1.2 E 18 2.38 321 213.83 303 301 282 283
5 13 1.2 E 24 0.85 79 107.85 74.5 74 69.3 69.7
6 16 1.2 E 3.7 2.81 40 37.81 37.7 37.5 35.1 35.3
7 19 1.2 E 966 0.73 6600 7806.45 6220 6180 5790 5820
8 22 1.2 E 109 0.94 724 733.16 682 678 636 639
9 24 1.12 SD 90 0.70 453 324.32 427 424 398 400
10 28 1.05 O 13 2.81 98 132.89 92.3 91.8 86 86.5
11 31 1.2 E 50 3.14 1063 961.28 1003 996 933 938
12 34 1.2 E 22 1.76 230 201.18 218 215 202 203
13 35 1.2 E 13 2.63 82 160 78.2 76.8 72 72.3
14 40 1.05 O 2.5 0.96 8 8.04 7.54 7.49 7.02 7.06
15 43 1.05 O 28 0.96 83 101.61 78.2 77.7 72.9 73.2
16 46 1.05 O 57 0.74 126 165.21 119 118 111 111
17 49 1.12 SD 91 0.36 156 168.87 147 146 137 138
18 52 1.05 O 8.2 1.90 41 55.39 38.6 38.4 36 36.2
19 55 1.05 O 6.3 0.34 18 7.52 17 16.9 15.8 15.9
20 58 1.2 E 25 1.09 130 145.25 123 122 114 115
21 63 1.2 E 10 0.39 15 17.3 14.1 14.1 13.2 13.2
Table 3.2: Calculated MRE
MRE using Inter.
COCOMO Model
MRE using
TRAP MF
MRE using TMF MRE using GBell
MF
MRE using Gauss2
MF
0.0859 0.0588 0.0637 0.1225 0.1176
0.1310 0.0583 0.0625 0.1200 0.1166
0.2150 0.0575 0.0637 0.1225 0.1175
0.3339 0.0560 0.0623 0.1215 0.1184
0.3651 0.0570 0.0632 0.1228 0.1177
0.0547 0.0575 0.0625 0.1225 0.1175
0.1828 0.0575 0.0636 0.1227 0.1182
0.0126 0.0580 0.0635 0.1215 0.1174
0.2840 0.0573 0.0640 0.1214 0.1170
0.3560 0.0581 0.0632 0.1224 0.1173
0.0957 0.0564 0.0630 0.1223 0.1176
0.1253 0.0521 0.0652 0.1217 0.1174
0.9512 0.0463 0.0634 0.1220 0.1183
0.0050 0.0575 0.0637 0.1225 0.1175
International Journal On Advanced Computer Theory And Engineering (IJACTE)
________________________________________________________________________________________________
________________________________________________________________________________________________
ISSN (Print): 2319-2526, Volume -4, Issue -4, 2015
6
0.2242 0.0578 0.0638 0.1216 0.1180
0.3111 0.0555 0.0635 0.1190 0.1190
0.0825 0.0577 0.0641 0.1218 0.1154
0.3509 0.0585 0.0634 0.1219 0.1171
0.5822 0.0555 0.0611 0.1222 0.1166
0.1173 0.0538 0.0615 0.1230 0.1154
0.1533 0.0600 0.0600 0.1200 0.1200
Table 3.3: Computed MMRE
Developmental Model MMRE
Intermediate COCOMO 0.2373
FL Trapezoidal MF 0.0565
FL Triangular MF 0.0630
FL GBell MF 0.1218
FL Gauss2 MF 0.1175
Figure 3.2: Comparison of MMRE
0
0.05
0.1
0.15
0.2
0.25
Intermediate COCOMO
FL TRAP MF FL TMF FL GBell MF FL Gauss2 MF
DEVELOPMENTAL MODELS
MMRE
MMRE
IV. CONCLUSION AND FUTURE
RESEARCH
This research work is to provide a technique for
software cost estimation that performs better than other
techniques on the accuracy of effort estimation.
In this research an improved approach to software
project effort is projected by the use of fuzzy sets rather
than classical intervals in the COCOMO model. This
study explores four fuzzy logic membership functions:
Fuzzy Triangular Membership Function, GBell
Membership Function, Gauss2 Membership Function
and Trapezoidal Membership Function. Results shows
that the fuzzy logic can predict the more accurate results
than Classical Model (COCOMO). Also it can be easily
seen that the value of MMRE for Trapezoidal
Membership Function is the lowest. So Trap. MF is the
best among the four fuzzy logic functions used.
However if the transition between the phases is
smoothly required then the linear MF’s like Trapezoidal
and Triangular are not suitable. In that case it was found
that Gauss2 MF has lower value of MMRE than GBell
MF and hence is better.
The above research work can be analyzed in terms of
feasibility and acceptance in the industry.It can be
deployed on COCOMO II environment with experts
providing required information for developing fuzzy sets
and an appropriate rule base.
Future research involves that various techniques like
neural networks can also be used for Software effort
estimation [3]. Fuzzy logic techniques can also be
compared with other criterions like VAF, BRE, MARE,
Prediction %.
By applying some more effort there is the possibility to
develop other customized membership functions, which
represents inputs more closely to tolerate uncertainty
and imprecision in inputs, and hence restricting the same
to be propagated to the outputs.
REFERENCES
[1] A. R. Gray, S. G. MacDonell, “Applications of
Fuzzy Logic to Software Metric Modelsfor
Development EffortEstimation”,Fuzzy
International Journal On Advanced Computer Theory And Engineering (IJACTE)
________________________________________________________________________________________________
________________________________________________________________________________________________
ISSN (Print): 2319-2526, Volume -4, Issue -4, 2015
7
Information Processing Society 1997 NAFIPS
97, Annual Meeting of the North American, 21&
24 September 1997, pp. 394 & 399.
[2] A.C. Hodgkinson and P.W. Garratt, “A
NeuroFuzzy Cost Estimator”, in Proceedings of
the 3rd International Conference on Software
Engineering and Applications – SAE, pp. 401-
406, 1999.
[3] A.R. Venkatachalam, “Software cost estimation
using artificial neural networks”, Proceedings of
the 1993 International Joint Conference on
Neural Networks, pp. 987-990, 1993.
[4] AbouBakarNauman, Romana Aziz.,
“Development of Simple Effort Estimation
Model based on Fuzzy Logic using Bayesian
Networks”, IJCA Special Issue on “Artificial
Intelligence Techniques - Novel Approaches &
Practical Applications” AIT, 2011.
[5] Albrecht A.J., and J.E. Gaffney, “Software
function, source lines of code, and development
effort prediction: a software science validation,”
IEEE Transactions on Software Engineering, pp.
639-648, November1983.
[6] A. Idri, T. M. Khoshgoftaar, A. Abran. “Can
NeuralNetworks be Easily Interpreted in
Software CostEstimation”, IEEE Trans. Software
Engineering, 2002,pp. 1162 & 1167.
[7] B. W. Boehm, Software Engineering
Economics,Englewood Cliffs, NJ, Prentice Hall,
1981.
[8] B. W. Boehm, C. Abts and S.Chulani, “Software
Development Cost Estimation Approaches- A
Survey”, Technical Reports, University of
Southern California Centre for Software
Engineering, usccse 2000-505.
[9] Boetticher, G.D., “An assessment of metric
contribution in the construction of a neural
network-based effort estimator”, Proceedings of
Second International Workshop on Soft
Computing Applied to Software Engineering,
2001.
[10] GeetikaBatra and MahimaTrivedi, “A Fuzzy
Approach for Software Effort Estimation”,
International Journal on Cybernetics &
Informatics (IJCI), Vol.2, No.1, pp. 9-15,
February 2013.
[11] ImanAttarzadeh and Siew Hock Ow, “Software
Development Effort Estimation based on a New
Fuzzy Logic Model”, International Journal of
Computer Theory and Engineering, Vol. 1, No. 4,
October 2009.
[12] ImanAttarzadeh and Siew Hock Ow, “A Novel
Algorithmic Cost Estimation Model Based on
Soft Computing Technique”, Journal of
Computer Science 6 (2): ISSN 1549-3636 ©
2010 Science Publications, pp. 117-125, 2010.
[13] Jones C., “Estimating Software Costs”, McGraw-
Hill, 1998.
[14] L. H. Putnam, “A general empirical solution to
the macro software sizing and estimating
problem”. IEEE Transactions on Software
Engineering, SE-4(4),pp. 345-361, 1978.
[15] Lotfi A. Zadeh, “Fuzzy sets”,Information and
Control, Vol. 8, pp. 338–353, 1965.
[16] Lotfi A. Zadeh, “Fuzzy Algorithms”,Information
and Control, Vol. 12, pp. 94-102, 1968.
[17] Lotfi A. Zadeh, “Outline of a new approach to
the analysis of complex systems and decision
processes”, IEEE Trans. Systems, Man and
Cybernetics, Vol. 3, No. 1, pp. 28–44, 1973.
[18] Lotfi A. Zadeh, “Making Computers Think like
People”, IEEE Spectrum, 8, pp. 26- 32, 1984.
[19] Lotfi A. Zadeh, “Fuzzy Logic, Neural Networks
and Soft Computing”, Communication of ACM
37(3): pp. 77-84, 1994.
[20] Lofti A. Zadeh, “The Future of Soft Computing”,
In Joint 9th IFSA World Congress and 20th
NAFIPS International Conference, Vancouver,
Canada,2001.[21] Mamdani, E.H., “Advances in
the linguistic synthesis of fuzzy controllers,”
International Journal of Man-Machine Studies,
Vol. 8, pp. 669-678, 1976.
[22] Mamdani, E.H., “Applications of fuzzy logic to
approximate reasoning using linguistic
synthesis,” IEEE Transactions on Computers,
Vol. 26, No. 12, pp. 1182-1191, 1977.
[23] PankajJalote, “An Integrated Approach to
Software Engineering”, Third Edition, Narosa
Publishing House, 2006.
[24] Prasad Reddy, Sudha.K.R., Rama Sree P ,
Ramesh, “Fuzzy Based Approach for Predicting
Software Development Effort” International
Journal of Software Engineering (IJSE), Vol. 1,
No. 1, pp. 1-11,May 2010.
[25] Rahul Kumar Yadav,Dr. S. Niranjan , “Software
Effort Estimation Using Fuzzy Logic: A
Review”, International Journal of Engineering
Research & Technology (IJERT) Vol. 2, No. 5,
ISSN: 2278-0181,pp. 1377-1384, May 2013.
[26] Roger S Pressman, “Software Engineering-A
Practitioner’s Approach”, Tata McGraw-Hill
Edition 2010.
[27] RoheetBhatnagar, MrinalKanti Ghose, Vandana
Bhattacharjee, “Predicting the Early Stage
Software Development Effort using Mamdani
FIS”, RoheetBhatnagar et al, (IJCSIT)
International Journal of Computer Science and
International Journal On Advanced Computer Theory And Engineering (IJACTE)
________________________________________________________________________________________________
________________________________________________________________________________________________
ISSN (Print): 2319-2526, Volume -4, Issue -4, 2015
8
Information Technologies, Vol. 2, No. 4, pp.
1675-1678, ISSN:0975 – 9646, 2011.
[28] RshmaChawla, Deepak Ahlawat, Mukesh
Kumar, “Software Development Effort
Estimation Techniques: A Review”, International
Journal of Electronics Communication and
Computer Engineering, Vol. 5, No. 5, ISSN
(Online):2249–071X, ISSN (Print): 2278–4209,
pp. 1166-1170,September 2014.
[29] RshmaChawla, Deepak Ahlawat, Mukesh
Kumar, “Improved Software Development Effort
Estimation Based on Fuzzy Logic Functions”,
International Journal of Engineering Sciences &
Research Technology, ISSN: 2277-9655,Vol. 3,
No. 12, pp. 529-535, December 2014.
[30] RshmaChawla, Deepak Ahlawat, “Improved
Software Development Effort Estimation Based
on Four Fuzzy Logic Functions”, International
Journal on Advanced Computer Theory and
Engineering (IJACTE), IRD India, ISSN (Print):
2319-2526, Vol. 4, No. 2, pp. 9-13, March 2015.
[31] The Math Works Inc., “Fuzzy logic toolbox- user
guide”, September 2010.