7
Palavras-chave: controle de qualidade, cartas de controle, capacidade do processo
e custo mínimo.
VILAS BOAS, Érika Bastos Buttenmüller. Quality study of material for ration factory
for cut chickens using control charts and techniques Taguchi of minimum cost –
2005. Dissertation (Mestrado em Desenvolvimento Regional e Agronegócio) –
Universidade Estadual do Oeste do Paraná - Campus de Toledo.
ABSTRACT
The objective of this work was to verify the statistical quality control of the raw
material used during the manufacturing of animal feed, which is being utilized for
broiler chicken feed in businesses located in the western region of the state of
Paraná. The raw material selected to be monitored were: corn and soy meal from
vegetable origin, and meat flour, viscus and feather flour from animal origin. The
variables that make up each group of raw material, such as humidity, raw protein,
soluble protein, phosphorus, acidity, raw fiber, uretic activity and ethereal extract
were collected during 2003 and 2004. The focus of this study of quality was on the
application of individual X and AM control charts, and EWMA charts, Tabular CUSUM
accumulated sum charts and V Mask CUSUM. An approach regarding the cost of
quality loss was utilized in order to determine the economic interval of inspection
related to the minimum cost, according to Taguchi’s techniques. Regarding the corn
raw material, the results show that the pondered control chart EWMA was the most
efficient when analyzing the studied variables. As far as the capability of the process
is concerned, we can conclude that only the humidity variable is below the desired
specifications. The soy meal raw material had the individual X and AM charts as the
most efficient and with an equivalent performance, and, regarding the process
capacity, only the variable urease is up to the minimum value recommended by the
CBAA. When it comes to the meat flour raw material, the tabular of the accumulated
sums chart CUSUM was the least efficient and, as far as its process capacity is
concerned, only the humidity variable is up to the minimum requirements required by
the CBAA. Regarding the feather flour raw material, the individual AM chart was the
most efficient, as far as the process capacity is concerned, none of the variables are
up to the minimum specifications required by the CBAA. When it comes to the viscus
flour raw material, the EWMA chars and the Tabular CUSUM were the most efficient,
having an equivalent performance, and regarding the process capacity, only the
humidity and acidity variables are up to minimum CBAA requirements. For the
analysis of the minimum costs, we observed that the costs increase with the process
tolerance increase (k) and decrease with the increase of the C
pl
or C
pu
values.
Regarding the optimum interval analysis of inspection, the results show that the
interval times decrease with the increase of the process tolerance (k), and increase
with the increase of the values of C
pl
or C
pu.
Keywords: quality control, control charts, process capability, minimum cost