INTRODUCTION TO DESIGN OF EXPERIMENT (DOE)

Design of experiment (DOE) is a body of knowledge, based upon statistical and other scientific disciplines, for efficient and effective planning of experiments and for making sound inferences from experimental data.

In an experiment, we deliberately change one or more process variables (or factors) in order to observe the effect the changes have on one or more response variables. The (statistical) design of experiments (DOE) is an efficient procedure for planning experiments so that the data obtained can be analyzed to yield valid and objective conclusions.

DOE begins with determining the objectives of an experiment and selecting the process factors for the study. An Experimental Design is the laying out of a detailed experimental plan in advance of doing the experiment. Well-chosen experimental designs maximize the amount of “information” that can be obtained for a given amount of experimental effort.

Used to evaluate which process inputs have a significant impact on the process output and what the target level of those inputs should be to achieve a desired result (Output).

Design of experiment defines the:

• Population to be studied,
• Randomisation Process
• Administration of Treatments,
• Sample size requirement
• Method of statistical analysis

The process of DOE may seem too cumbersome and extensive to comprehend at the first try.

But, there is a need to understand the use of design of experiment  in product and process research and development to achieve product excellence.

BASIC PRINCIPLES OF DESIGN OF EXPERIMENT

Following the Basic Principles of Design of Experiment  which      include:

• Randomisation
• Replication and
• Local Control

One can easily comprehend the Idea of DOE and easily implement it in product and process research.