The Role of Statistics in Engineering
Engineering is the field of solving problems of interest to society by the efficient application of scientific principles. The engineers effectively plan experiments, collect data, analyze and interpret the data, and understand how the observed data are related to the model they have proposed for the problem under study. The field of statistics deals with the collection, presentation, analysis and use of data to make decisions, solve problems and design products and processes. Hence the field of statistics and engineering are interrelated. In engineering, statistical techniques can be a powerful aid in designing new products and systems, improving existing designs and designing, developing and improving production processes.
Statistics has various engineering applications in testing materials, performance test of systems, robotics and automation in general, control of production process and so on. It has roles in different fields of engineering such as:
- Design of experiments uses statistical techniques to test and construct models of engineering components and systems.
- Quality control and process control use statistics as a tool to manage conformance to specifications of manufacturing processes and their products.
- Time and methods engineering use statistics to study repetitive operations in manufacturing in order set standards and find optimum (in some sense) manufacturing procedures
- Reliability engineering uses statistics to measure the ability of a system to perform for its intended function (and time) and has tools for improving performance.
- Probabilistic design uses statistics in the use of probability in product and system design.
Some of the important functions of statistics are:
- To represent the facts from numerical figures.
- To help in classification of data, predicting future trends and formulating policies.
- To determine the relationship between different phenomena.
- To have an idea about occurrences or non-occurrences of certain events and draw valid inferences or conclusions.
Limitations of Statistics
- Statistics deals with the aggregates. It does not study individuals. An individual, to a statistician has no significance except the fact that it is a part of the aggregate.
- Statistics is concerned with quantitative data. However, qualitative data also can be converted to quantitative data by providing a numerical description to the corresponding qualitative data.
- Statistical laws are not exact. Since these laws are probabilistic in nature, so they do not hold well in every case. It is also said that statistics itself is not an absolute measure. It provides precise result minimizing error as much as possible.
- Statistics is liable to be misused. Statistics neither proves nor disproves anything. The use of statistical tools by inexperienced and untrained persons might lead to very fallacious conclusions. In words of W.I. King, “Statistics are like clay which you can make a God or a Devil as you please”. Therefore, statistical methods are the most dangerous tools in a hand of the inexpert. So only, the experts or statisticians can handle statistical data properly.