How to draft an impeller vane profile using either Kaplan/Stepanoff "Error triangle method" or Pfleiderer "point by point blade design method".

I want t draft an impeller vane profile of for a centrifugal pump impeller.

I have the OD of the impeller, impeller eye diameter, vane angle and most other details needed.

I just cannot grasp the method to draft the vanes using the two most popular methods used around the world.

The two methods are
1) The Error triangle method by Kaplan/Stepanoff
2) point by point blade design method by Pfleiderer

Can anyone help me understand the procedure for drafting the vanes by either of these 2 methods.

I have done all the research online and found some articles but all of them are not clear and understandable.

Anyone with a background in design of Pumps will be of great help as I am designing a Pump casing and impeller.

I have figured out the method of getting the sections for the volute casing but not able to figure out the impeller.

I have attached an article from International Journal of Scientific Engineering and Research and there is a method mentioned but I am not able to understand it.