What is Excel Process Modelling?

Here a ‘process’ means a series of calculations that can be described by a flowsheet. Excel process modelling is a framework to efficiently enable Excel users to create a system of models that can be integrated by a flowsheet.

Originally Excel Process Modelling was included within mineral processing simulation courses; but have now been created as a standalone series useful for any quantitative analyst.

There are numerous variations of the course being made available internationally; however the course series listed here provides a basic overview.


A stream flow represents a set of data.

A unit represents a chance in stream information (could be a calculation process or a phyisical process)


For example, in financial modelling, a set of data can be a list of products that a company has sold, and a unit can calculate the total sales.




In many companies, chaos is the norm

Many professionals use Excel; indeed it is likely that 90% of engineers and scientists use Excel on a daily basis.

Yet very few engineers and scientists have been taught how to use Excel efficiently.

In many instances this situation is considered satisfactory (albeit recognising that it may not be) because they are not required to share their Excel workbooks with others.

But when they are required to share, many problems emerge:

Excel workbooks may be:

Unstructured – apparently adhoc collection of numbers that appear arbitrarily linked to other adhoc numbers.

Unsuspecting colleagues  may now be forced (as directed by their Manager) to spend  considerable  time trying to unravel the exact calculation thread; only then to be additionally forced to increase the complexity of the workbooks by adding more unstructured worksheets and providing further poorly linked workbooks.

Surprisingly such an unstructured work environment is akin to a naughty child who never tidies up his room.  It is amazing how many adults would not tolerate messy rooms from their children; yet continue to allow a messy work environment in Excel.  Why?

Confusing Excel

Creating Structure

There are of course many reasons for the current chaos but the primary reason is that staff and Managers have never been taught to organise Excel in a structured manner; and are not aware of the huge work efficiency gain that can be obtained from just a minimum knowledge.

The series of courses being offered provides a framework to consider how to convert messy Excel workbooks into well-structured flowsheet-driven workbooks which are a pleasure to distribute to your colleagues and clients and could well increase your Excel efficiency by over 100%!

All the courses follow a theme of flowsheet-based Excel process modelling

This provides a focus for structured and efficient use of Excel (even if the participant decides not to specifically develop complex flowsheet-based process modelling)

All courses are 1 day and I have split the courses into two (using green and yellow highlights) to allow two four hour courses.

I have used a code of starting with XLPM (Excel Process Modelling).

Here Excel is abbreviated by XL.



The instructor is Dr Stephen Gay  from MIDAS Tech International.  Stephen has been a mathematical modeller in various positions (Physical Oceanography, Mineral Processing) and has mainly focused on developing process modelling software for mineral processing.  However  Stephen decided to generalise the software for any process that can be described by a flowsheet resulting in the various courses being made available.  Stephen is aiming to target a 100% efficiency increase in the use of Excel by participants through the use of simple concepts and small applications that provide basic assistance.

Stephen is an International speaker who has given various courses in Australia, South Africa, Iran and Chile.  He is the author of over 50 refereed papers.


Excel applications made available by the instructor

Various applications will be made available to participants freely so as to complete the course material.  Applications outside the scope of the course will be made available at discounted rates.  This software is subject to standard copyright and cannot be distributed to associates of participants.

MIDAS Tech is the Company owned by Stephen and has a broad range of activities.  In this document we only discuss courses being offered for Excel for general users.  More specialist software (for say mineral processors) are in separate course series.

The courses discussed here are aimed at two target participants:

  1. Excel undergraduates and professionals
  2. Managers

Because of Stephen’s background in engineering and science the courses are heavily steered toward these two groups; but other professionals would still get much out of the course.

However (in the absence of this course series) there is currently a void of Excel courses for engineers and scientists.  This is the only course series available in the world that focused on flowsheet-based modelling.

Will the course series make you an expert?

This of course is a good question.  To become totally proficient in Excel takes a long time varying depending on your previous knowledge of spreadsheets and VBA. The course does not specifically target making you an expert; what it does do is provide you with the knowledge to overcome the hurdles that may prohibit you from reaching your potential.  For example many engineers do not even know that VBA exists!  So even something as simple as creating a library of commonly used functions and collating them in addins provides an immediate efficiency gain.

The course is a series ; however notice in the final undergraduate course: XPM06 participants are asked to identify what skills they have learnt that increase efficiency and quantify by what amount.