Page 1 of 7
Journal for Studies in Management and Planning
Available at http://edupediapublications.org/journals/index.php/JSMaP/
e-ISSN: 2395-0463
Volume 02 Issue 2
February 2016
Available online: http://edupediapublications.org/journals/index.php/JSMaP/ P a g e | 389
Assessing the Quality Standard of Indigenous Brewery
Companies in Nigeria
A Case Study of Savannah Soft Drink, Onitsha Anambra State
1. C. E. Okorie,
2. Adubisi obinna
1,2Department of Mathematics and Statistics, Federal University Wukari, 200 Katsina-Ala Road,
P.M.B. 1020, Wukari, Taraba State, Nigeria
E-mail: Chyokanmelu@yahoo.com, obinnadubsi@yahoo.com
ABSTRACT
The purpose of this study is to assess the
quality standard of Savannah Soft drink, a
product of an indigenous Life-breweries
Nigeria Limited, Onitsha through control
charts in order to ascertain that it meets up
with the standards stipulated by the Standard
organization of Nigeria and specification
limits set down by the brewery company. Data
on two major components; sugar
concentration and Carbon IV Oxide
concentration used in the production process
of the soft drink were collected for the purpose
of this research from the company’s
production process for six consecutive times in
a day. The data spanned a period of twenty- eight days at an interval of 7 days per month,
from January to April. The Chi-square test,
Student t-distribution test and Control Charts
were used to analyse the data. The results
indicated that the concentration of sugar in
the production process of Savannah soft drink
is statistically in-control whereas the
concentration of Carbon IV Oxide is not
completely in control as indicated in the mean
quality control charts.
Key words: Quality, control charts, Chi-square
test, Students t-test.
1. INTRODUCTION
The concept of specialization of labour was
introduced during the Industrial Revolution.
As a result, a worker no longer made the entire
product but only a portion of the product. This
change brought about a decline in
workmanship. Because most products
manufactured during the early periods were
not complicated and quality was not in any
way affected. As products became more
complicated and jobs also became more
specialized due to advancement in technology,
it became necessary to inspect products during
or after the manufacturing process. Such roles
were, in part aimed at the maintenance of
quality. In modern times, factory inspection
and research, pure food and drug acts,
activities of professional societies, all have
sought for years to ensure the quality of
manufacturing product outputs. The basic
reason the Federal government of Nigeria
came up with various legislations to protect
customers from buying inferior made goods.
Among the various legislations is the Standard
Organization of Nigeria (SON), was
established in 1974 with a single mandate to
monitor the quality of goods that are brought
into the Nigeria market. Firms with high
quality goods were issued certificate of high
quality by the Standard Organization of
Nigeria (SON) after proper inspection of the
products.
1.1 STATEMENT OF THE PROBLEM
Many indigenous industries are going out of
existence because of the fact that they are
producing goods that are of low quality which
attracts no demand by consumers. It is because
of this that consumers prefer foreign goods to
Nigeria home-made goods with the mind-set
that they are more of high quality. On this
premise this study is based to investigate the
quality standard of Savannah soft drink, a
product of an indigenous brewery company in
Nigeria.
Page 2 of 7
Journal for Studies in Management and Planning
Available at http://edupediapublications.org/journals/index.php/JSMaP/
e-ISSN: 2395-0463
Volume 02 Issue 2
February 2016
Available online: http://edupediapublications.org/journals/index.php/JSMaP/ P a g e | 390
1.2 PURPOSE OF THE STUDY
This study is carried out to assess the quality
standard of Savannah soft drink, product of
Life-Breweries Nigeria Limited, through the
following aims and objective.
(1) To check whether Savannah soft drink
conforms to the standards set by the Standard
Organization of Nigeria (SON).
(2) To verify whether some of the
components used in the production process
of Savannah soft drink are combined in the
proper proportions by the Brewery company
in ascertain that will not be harmful to
consumers health.
(3) To find out the causes of deviations in
the product, if there is any and also to
suggest solutions to the deviation.
2. RESEARCH LITERATURE
The World book Dictionary (page 1703)
defined quality control as the inspection of
manufactured products from the raw materials
that go into them to the finished form to
ensure that they meet the standards of quality
set up by the manufacturer. However, various
authors define quality control with respect to
their fields of expertise. Quality control is also
defined as a means of checking, determining
and predicting the quality level of a product.
Norman et al in their book Glossary of
Marketing terms page 159, defined quality
control as important procedure usually
involving the random inspection of goods with
a view to maintain specified standards.
Duncan (1959) stated that quality generally is
the degree of excellence, perfection and
control means to administer, manage, direct or
regulate to achieve excellence. While Mittag
et al (1993) defined quality control as all the
inspection procedures administered during the
process of manufacturing which are suitable to
give information about the state of the process
and thus make it possible to intervene in the
process with the intention to maintain the
quality characteristic of the product within the
specified tolerance limit. Banjoko (1994)
viewed that quality control programs must
begin with the building of quality level that is
consistent with the organizational objectives,
customer’s specifications and process
capability. He also said that statistical quality
control efforts are initiated to enhance the
quality of products being produced and sent
out to the consumers. Bester field (1986)
concluded that quality control is involved with
the activities of specification, design,
production or installation, inspection and
review of usage. He also noted that statistical
quality control is a branch of quality control
which involves collection of data, analysis and
interpretation of data for use in quality control
activities. Skinner (1973), in his book
Commerce for Secretarial and Business
studies noted that the product of a firm can be
standardized so that every unit is identical and
there are no problems of selection or branding.
He concluded that goods cannot be called
what they are not and that if the buyer
considers that the warranties as to quality and
fitness have not been complied with, he may
sue the supplier for damages or indeed for
breach of contract if it can be proved that a
condition has been unfulfilled. Purchasers of
lots subsequently found to be below the agreed
standard would be compensated either by an
agreed adjustment or by the verdict of a panel
of arbitrators.
Quality control ensures uniformity,
wholesomeness, product reliability and quality
assurance. On the other hand, statistical
quality control is new and early applications
were made in biological and social sciences,
but not until the 1920’s that application of
statistical theory to quality control became
much more effective. Statistical quality control
has been recognized and is accepted as a vital
tool for quality control. Its scope is to deal
with collection, analysis, interpretation of
numerical data obtained by inspection and test
of the products. Statistical quality control
makes the quality of a given product possible
enough to have some kind of qualitative
measure of quality assurance. This method
Page 3 of 7
Journal for Studies in Management and Planning
Available at http://edupediapublications.org/journals/index.php/JSMaP/
e-ISSN: 2395-0463
Volume 02 Issue 2
February 2016
Available online: http://edupediapublications.org/journals/index.php/JSMaP/ P a g e | 391
however, permits and provides a statistical
inference technique.
3. MATERIALS AND METHODS
The various methods were used for the
analysis of the data to assess the quality
standard of the brewery company.
3.1 Test for Normality
The chi-square test is used to investigate the
normality of the data on sugar concentration
and Carbon IV Oxide which determine the
taste of the soft drink. It measures the
closeness of the observed number
( ) Oi
and
occurrences of the expected number
( ) Ei
;
i 1,2,...k . It can be shown that if
( ) Oi
is the
observed frequency for the
th i
class interval
and
( ) Ei
is the corresponding expected
frequency, then the statistic is
n
i i
i i
E
O E
1
2
(1)
Hypothesis:
: H0
Taste is normally distributed
: H1
Taste is not normally distributed.
Decision Rule: Testing at 5% level of
significance, we reject the null hypothesis, H0
if the Chi-square calculated value is greater
than Chi-square critical value χv
2
at v = k −
m − 1 degrees of freedom.
3.2 Student t – distribution test
The t-distribution test belongs to a one
parameter family of distributions and is
completely specified by its degree of freedom.
The distribution has a mean and a mode both
equal to 0 and a variance of
,
r 2
r
(r > 2)
which is generally greater than 1 but
approaches 1 as r becomes very large. The
degree of freedom r = n − 1 when applied to
problems involving a single sample. Since in
this work, n = 28 is less than 30 and the
variance (σ
2
) of the population is not known,
t − distribution formula to be used are;
s n
x
t
/
(2)
Hypothesis
H0: μ = μ0
H1: μ ≠ μ0
Decision Rule: From the alternative
hypothesis, the test is a two tailed test. We
reject H0 if the calculated t-test statistic value
is greater than the critical t
1−
α
2
,v
value with
v = n − 1 degrees of freedom at level of
significance, α = 0.05.
3.3 Control Charts:
Control charts may be defined as; A
chronological (hour by hour, day by day)
graphical comparison of actual product quality
characteristics with limits reflecting the ability
to produce as shown by past experience on the
product characteristics (Feigenbarm, 1961,
page 250). However, a control chart can
simply be said to be a graphical tool for
conducting periodic significance tests as an aid
to maintain acceptable standards of quality.
The control chart can therefore be said to be a
tool used primarily for analysing data either
discrete or continuous, which are generated
over a time period. In any production process,
some variation in quality is unavoidable and
the theory behind the control chart originated
by W. A. Shewhart is that, this variation can
be divided into two categories: random
variation and variation due to assignable
causes. Certain variations in quality are due to
causes over which we have some degree of
control, such as different quality of raw
materials or new or unskilled workers; we call
these assignable causes of variation. The
random variation is the result of each cause
being slight; by and large nothing can be done
about this cause of variation except to modify
the process,
