Faculdade de Ciências e Tecnologia

Quality Planning and Control



Academic unit

Faculdade de Ciências e Tecnologia


Departamento de Engenharia Mecânica e Industrial



Teacher in charge

José Fernando Gomes Requeijo, Rogério Salema Araújo Puga Leal

Weekly hours


Total hours


Teaching language



The main purpose of Quality Planning and Control is to provide to students the ability to:

-Understand the role of Design of Experiments, Taguchi methods and Statistical Process Control (SPC) within a TQM environment;

-Recognise when experimental design techniques should be applied;

-Plan and carry out full and fractional factorial designs and analyse the experimental results;

-Use the Taguchi methods for experimental design and compare them to traditional methods;

-Find the best parameters combination for reducing process variability;

-Recognise the importance SPC might have in product and process improvement;

-Apply the methodology for implementing statistical control charts;

-Study the process capability.

-Implement the 6-Sigma methodology and use Design of Experiments and SPC within the 6-Sigma approach.

Simultaneously, through the teaching and learning practices, the students will develop their skills in problem solving, team working, critical thinking and communication.

Subject matter


2.Statistics in quality modelling

3.Design of Experiments (DoE)


-DoE of 1 and 2 factors with many levels

-Full Factorial Design

-Two-level Factorial Designs

-Two-level Fractional Factorial Designs

-Three-level Factorial Design

4.Taguchi Methods

-Loss Function

-Signal-to-Noise Ratio

-Confirmatory trials

5.Statistical Process Control

-Causes of variation

-Traditional Control Charts for Variables

- Control Charts for Attributes

-Process capability

6.Six-Sigma Methodology


-Montgomery, D. C. (2001), Introduction to Statistical Quality Control, 4.ª ed., John Wiley & Sons, New York-

Montgomery, D. C. (2001), Design and Analysis of Experiments, 5.ª ed., John Wiley & Sons, New York

-Peace, G. S., (1993), Taguchi Methods: A Hands-On Approach to Quality Engineering, Addison-Wesley Publishing Company, New York.

-Pereira, Z.L. e Requeijo, J.G. (2012), Qualidade: Planeamento e Controlo Estatístico de Processos,2ª Edição, FFCT-UNL, Lisboa

-Pyzdek, T. (1999), Quality Engineering Handbook, Marcel Dekker, New York

-Ryan, T. P. (2000), Statistical Methods for Quality Improvement, 2.ª ed., John Wiley & Sons, New York

-Taguchi, G. (1986), Introduction to Quality Engineering, UNIPUB, White Plains, New York.

Teaching method

  • Theoretical lectures
  • Problem-solving sessions
  •  Laboratory sessions on Design of Experiments and Statistical Process Control.

The main concepts, approaches and techniques are explained in the theoretical lectures (2 hours per week). The lecture starts with a brief summary of the subjects exposed in the previous lecture, followed by the explanation of subjects planned for that day, stimulating as much as possible the students participation. In the problem-solving sessions (3 hours per week), the students, which are grouped in teams, solve exercises about the main topics. The teams also have to solve a few exercises as homework. In the laboratory sessions, the teams have to perform one small project. This project applies the Design of Experiments. A specific software such as Statistica is used for analysing the experimental results, which also provides some training on this important tool.

Evaluation method

 -To be admitted in the final exam, the student must participate in teamwork activities (one lab group project).

- This frequency is valid for the following two academic years.

 -The final grade takes into consideration the following components: (1) one lab group project, (2) two assessment tests or final exam.

- To be approved in the course is required a minimum grade ten values in each of these components

- The final classification is obtained through lab group project with the weight 1 and the assessment tests / final exam with weight 2. A minimum classification of seven is required in the second assessment test.