An information processing apparatus for a manufacturing data analysis system, comprising: an input unit configured to input data of a plurality of measuring instruments and sensors, the input data including values of multiple variables including three or more variables, the values of multiple variables representing one or more of measurement values for a shape of a product, a voltage and a current indicating the state of a processing machine acquired in a manufacturing process of the product, temperature and humidity of a factory; a control unit configured to calculate an index of a relation between any two variables for all variables of the multiple variables, wherein the index is indicative of correlations or cause-effect relations between any two variables; output, via a user interface, a graph indicating the calculated relation between any two variables, wherein variables are expressed as nodes and the correlations or cause-effect relations between the variables are expressed as links in the graph; accept, via the user interface, a selection of a variable of interest and a selection of a number n ≥ 2 of explanatory variables among the multiple variables, the explanatory variables having an influence on the variable of interest, wherein the variable of interest is indicative of information indicating a finish of the product, wherein the variable of interest is selected by a node selection operation in the graph; and output, via the user interface, first information indicating a strength of a relation between the variable of interest and combinations of the explanatory variables for all combinations of the n explanatory variables; and output, via the user interface, the combinations of explanatory variables in which the strength of the relation is equal to or larger than or is equal to or smaller than a predetermined threshold value. an input unit configured to input data of a plurality of measuring instruments and sensors, the input data including values of multiple variables including three or more variables, the values of multiple variables representing one or more of measurement values for a shape of a product, a voltage and a current indicating the state of a processing machine acquired in a manufacturing process of the product, temperature and humidity of a factory; a control unit configured to calculate an index of a relation between any two variables for all variables of the multiple variables, wherein the index is indicative of correlations or cause-effect relations between any two variables; output, via a user interface, a graph indicating the calculated relation between any two variables, wherein variables are expressed as nodes and the correlations or cause-effect relations between the variables are expressed as links in the graph; accept, via the user interface, a selection of a variable of interest and a selection of a number n ≥ 2 of explanatory variables among the multiple variables, the explanatory variables having an influence on the variable of interest, wherein the variable of interest is indicative of information indicating a finish of the product, wherein the variable of interest is selected by a node selection operation in the graph; and output, via the user interface, first information indicating a strength of a relation between the variable of interest and combinations of the explanatory variables for all combinations of the n explanatory variables; and output, via the user interface, the combinations of explanatory variables in which the strength of the relation is equal to or larger than or is equal to or smaller than a predetermined threshold value.