Statistical process control charts for the analysis of water consumption: a case study at a university
DOI:
https://doi.org/10.46421/entac.v20i1.6196Keywords:
Monitoring, Water consumption, Statistical process control, Graphical analysis, Consumption patternAbstract
This study analyzes water consumption at Universidade do Estado de Santa Catarina (UDESC – CCT) located in southern Brazil using Statistical Process Control Charts. This article examines the monthly variations in water consumption over 53 months (2017-2022), including the period of the COVID-19 pandemic. The study was conducted at a Public Higher Education Institution, utilizing Shewhart, Exponentially Weighted Moving Average (EWMA), and Cumulative Sum (CUSUM) charts. These charts provide insights into changes in consumption, notably influenced by the COVID-19 pandemic. The study is divided into two phases: Phase 1 establishes reference lines to guide the analysis, while Phase 2 evaluates all data points in relation to these benchmarks. Normality tests on the reference data were used to validate Phase 1. A gradual decrease in water consumption during the lockdown months corresponds to reduced campus traffic. Control charts can be easily integrated into digitized water consumption measurement systems due to their simplicity of programming and interpretation.
References
SILVA, T. R.; MARIOTTI, M. C.; BRIDI, A. Aprendendo a lidar com as mudanças de
rotina devido ao Covid-19: Orientações Práticas para Rotinas
Saudáveis/Learning to deal with change routine due to COVID-19: guidelines
healthy routine practices. Revista Interinstitucional Brasileira de Terapia
Ocupacional - REVISBRATO, v. 4, n. 3, p. 519–528, 15 maio 2020.
ONU. COVID-19 highlights the need for access to clean water. [Tajiquistão],
Disponível em: <https://www.undp.org/tajikistan/stories/covid-19-
highlights-need-access-clean-water>. Acesso em: 7 maio 2024.
OHCHR - Office of the United Nations High Commissioner for Human Rights.
COVID-19 will not be stopped without providing safe water to people living in
vulnerable situations. OHCHR, 20 mar. 2020. Disponível em:
<https://www.ohchr.org/en/press-releases/2020/03/covid-19-will-not-be-
stopped-without-providing-safe-water-people-living>. Acesso em: 7 maio 2024.
MONTGOMERY, D. C. Introdução ao Controle Estatístico da Qualidade - 7ª Ed.
Rio de Janeiro: LTC, 2016.
VINING, G. Technical Advice: Phase I and phase II control charts. Quality
Engineering, v. 21, n. 4, p. 478-479, 2009. Disponível em:
<http://dx.doi.org/10.1080/08982110903185736>.
STEMANN, D.; WEIHS, C. The EWMA-X-S-control chart and its performance in
the case of precise and imprecise data. Statistical papers, v. 42, n. 2, p. 207–
, 1 abr. 2001.
WALTER, O. M. F. C. et al. Aplicação individual e combinada dos gráficos de
controle Shewhart e CUSUM: uma aplicação no setor metal mecânico. Gestão
& Produção, v. 20, n. 2, p. 271–286, jun. 2013.
ALVES, C. DA C. Gráficos de Controle CUSUM: um enfoque dinâmico para a
análise estatística de processos. Florianópolis 2003. [s.l: s.n.]. Disponível em:
<https://repositorio.ufsc.br/xmlui/bitstream/handle/123456789/84565/192006.
pdf?sequence=1&isAllowed=y>. Acesso em: 8 maio. 2024.
ALVES, C. DA C. et al. A utilização de gráficos de controle de soma acumulada
(cusum) para monitoramento de um processo de usinagem. Cadernos do IME -
Série Estatística, v. 27, n. 0, 1 dez. 2009.
GIL, A. C. Como elaborar Projetos de Pesquisa. 4o ed. São Paulo: Atlas, 2002.
Disponível em:
<https://files.cercomp.ufg.br/weby/up/150/o/Anexo_C1_como_elaborar_projet
o_de_pesquisa_-_antonio_carlos_gil.pdf>.
R CORE TEAM (2021). R: A language and environment for statistical computing.
R Foundation for Statistical Computing, Vienna, Austria. Disponível em:
<https://www.R-project.org/> .
SCRUCCA, L. (2004). qcc: an R package for quality control charting and
statistical process control. R News 4/1, 11-17. Disponível em:
project.org/web/packages/qcc/qcc.pdf>.
HENNING, E.; ALVES, C. C.; SAMOHYL, R. W. Gráficos de controle multivariados
MEWMA e MCUSUM em ambiente R. In: SIMPÓSIO NACIONAL DE
PROBABILIDADE E ESTATÍSTICA, 18., 2008, Estância de São Pedro. Anais…
Estância de São Pedro, 2008.
NELSON, L. S. The Shewhart Control Chart—Tests for Special Causes. Journal of
Quality Technology, v. 16, n. 4, p. 237–239, out. 1984.
MOROTE, Á.-F. et al. Water Consumption and Management in Schools in the City
of Alicante (Southern Spain) (2000–2017): Free Water Helps Promote Saving
Water? Water, v. 12, n. 4, p. 1052, 8 abr. 2020.
FONSECA, J. F. R. INSTITUTO FEDERAL DO ESPÍRITO SANTO PROGRAMA DE PÓS-
GRADUAÇÃO EM TECNOLOGIAS SUSTENTÁVEIS MESTRADO PROFISSIONAL EM
TECNOLOGIAS SUSTENTÁVEIS JULIANA FREITAS RAMOS DA FONSECA. USO
RACIONAL DA ÁGUA POTÁVEL NO IFES -ESTUDO DE CASO CAMPUS VITÓRIA.
Vitória 2021. [s.l: s.n.]. Disponível em:
<https://repositorio.ifes.edu.br/bitstream/handle/123456789/1965/DISSERTA%
c3%87%c3%83O_Uso_Racional_%c3%81gua_Pot%c3%a1vel_Ifes.pdf?sequence=
&isAllowed=y>. Acesso em: 8 maio. 2024.
OGUNBODE, T. O.; ASIFAT, J. T. Comparative Assessment of Pre-COVID-19 and
Post-COVID-19 Lockdown Water Demand in Selected Institutions of Learning in
a Growing Community in Nigeria. European Journal of Basic Medical Sciences, v.
, n. 4, p. 38–45, 31 ago. 2021.
