Probability is a concept which is simple but powerful if applied correctly. A Very Simple example is that when there is coin tossed up,there are two outcomes possible. HEAD and Tail. If the coin has no bias, both the out comes are equally possible. We say that there is a possibility of 50% (0.5) each. Let us extend this to another commonly used game. If we throw a dice, there Read More …

# Category: Statistics

## Basic Statistics – II What is a Variable and What are variable types

Variable is a characteristic, number, or quantity that increases or decreases over time, or takes different values in different situations. The variables are the basic units used in statistics for measuring , collecting and analyzing. Variables can be classified in to different categories depending on the usage at the point of analysis. The different variable types are Dependent and Independent Variable types An independent Variable can take any value and can be controlled Read More …

## What is KPI (Key Performance Indicator)

Key Performance Indicators (KPI’s) are the critical success factors that define an organization’s progress. KPI’s must be measurable, and are trended over time to show progress and take action where needed. These can be defined at various levels in an organization, from the CEO to the sales team to the manufacturing floor. These are the statistics generated from the organizational metrics The KPIs are to be simple, Measurable, repeatable, and Read More …

## What is Design of Experiments (DOE)

Design of Experiments (DOE) is a structured approach for varying process and/or product factors (x’s) and quantifying their effects on process outputs (y’s), so that those outputs can be controlled to optimal levels. DOE deals with identification of critical factors and their response variables, and the magnitude of the response for each level of the critical factors. DoE is also used to understand the interaction between the various critical factors Read More …

## Sixth principle of SPC – causes for Variation

According to the sixth principle of SPC a frequency distribution will be deviating from normal distribution, only in the presence of any assignable cause. A frequency distribution is a tally of measurements that shows the number of times the measurement is included int he tally. From this frequency distribution we can see if there are only chance causes present in the process of any assignable causes are acting. If there Read More …

## Fifth Principle of SPC – shape of the distribution

The Fifth Principle of SPC states that it is possible to determine the shape of the distribution form the measurements of any process. We can learn abut what the process is doing, against what we want the process to do. For this we need to measure the output of the process with the design specifications.the process can be altered if we donot like the comparison, especially if we see a variation. Read More …

## Fourth Principle of SPC – the shape is like a bell

Fourth Principle of SPC is logical extension of the third principle which is covered in my last post. In which it was said that most measurements will be clustered around the middle. In Fact it was proved by statisticians that we can make failry accurate predictions of the percentage measurements in the various sections of the frequency distribution curve. Frequency curve with normal distribution You can see this graph Most Read More …