To solve your initial problem, replace table
by table*
. Your caption is actually centered, but only centered with respect to one column, since table
marks a one-column float, whereas table*
is a float spanning both columns.
The code below suggests two further changes. First, do not rescale the table, but instead avoid vertical bars (they just take up space and rather distract than help in orientation) and use the tabularx
environment that allows you to automatically have equally spaced columns. Moreover, the booktabs
package results in nicely spaced rows and lines.

\listfiles
\documentclass[journal,compsoc]{IEEEtran}
\usepackage{graphicx}
\usepackage{tabularx,booktabs}
\usepackage{blindtext}% Only needed for dummy text
\begin{document}
\title{ABC Study}
\author{The author}
\maketitle
\section{RM}
For the results of the search process, see table~\ref{ts}.
\begin{table*}
\centering
\caption{Results of the search process.}\label{ts}
\begin{tabularx}{\textwidth}{XlXXXXX}
\toprule
Authors with Ref. & Year & Theme & Parameter & Technique & Method Validation & Dimension
\\\midrule
B.~Tansey, E.~Stroulia & 2007
& Estimation of potential business value of evolving SOA applications
& effort estimation & COCOMO2 and real options theory & not shown &
\\\midrule
L.~Santillo & 2007
& Discusses the boundary problem from the software measurement and estimation perspective
& size estimation & COSMIC functional size measurement for SOA environment & not shown &
\\\midrule
J.~Lee et al. & 2008
& Estimating project plans and service costs of packaged business process applications
& cost estimation & Normative and constructive models & not shown &
\\\bottomrule
\end{tabularx}
\end{table*}
\Blindtext
\Blindtext
\end{document}
In the code above I have added \listfiles
as the first line. This makes LaTeX write the list of used files to the log file (including version infos). The code above works for the following versions of the packages:
*File List*
IEEEtran.cls 2015/08/26 V1.8b by Michael Shell
ot1ppl.fd 2001/06/04 font definitions for OT1/ppl.
graphicx.sty 2014/10/28 v1.0g Enhanced LaTeX Graphics (DPC,SPQR)
keyval.sty 2014/10/28 v1.15 key=value parser (DPC)
graphics.sty 2016/10/09 v1.0u Standard LaTeX Graphics (DPC,SPQR)
trig.sty 2016/01/03 v1.10 sin cos tan (DPC)
graphics.cfg 2016/06/04 v1.11 sample graphics configuration
pdftex.def 2017/01/12 v0.06k Graphics/color for pdfTeX
infwarerr.sty 2016/05/16 v1.4 Providing info/warning/error messages (HO)
ltxcmds.sty 2016/05/16 v1.23 LaTeX kernel commands for general use (HO)
tabularx.sty 2016/02/03 v2.11 `tabularx' package (DPC)
array.sty 2016/10/06 v2.4d Tabular extension package (FMi)
booktabs.sty 2016/04/27 v1.618033 publication quality tables
blindtext.sty 2012/01/06 V2.0 blindtext-Package
xspace.sty 2014/10/28 v1.13 Space after command names (DPC,MH)
supp-pdf.mkii
pdftexcmds.sty 2017/03/19 v0.25 Utility functions of pdfTeX for LuaTeX (HO)
ifluatex.sty 2016/05/16 v1.4 Provides the ifluatex switch (HO)
ifpdf.sty 2017/03/15 v3.2 Provides the ifpdf switch
epstopdf-base.sty 2016/05/15 v2.6 Base part for package epstopdf
grfext.sty 2016/05/16 v1.2 Manage graphics extensions (HO)
kvdefinekeys.sty 2016/05/16 v1.4 Define keys (HO)
kvoptions.sty 2016/05/16 v3.12 Key value format for package options (HO)
kvsetkeys.sty 2016/05/16 v1.17 Key value parser (HO)
etexcmds.sty 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
epstopdf-sys.cfg 2010/07/13 v1.3 Configuration of (r)epstopdf for TeX Live
ot1phv.fd 2001/06/04 scalable font definitions for OT1/phv.
upzd.fd 2001/06/04 font definitions for U/pzd.
***********
table
bytable*
.