Joseph Guillaume – Integration and Implementation Insights

Blackboxing unknown unknowns through vulnerability analysis

August 11, 2023November 19, 2019

By Joseph Guillaume

Author - Joseph Guillaume — Joseph Guillaume (biography)

What’s a productive way to think about undesirable outcomes and how to avoid them, especially in an unpredictable future full of unknown unknowns? Here I describe the technique of vulnerability analysis, which essentially has three steps:

Step 1: Identify undesirable outcomes, to be avoided
Step 2: Look for conditions that can lead to such outcomes, ie. vulnerabilities
Step 3: Manage the system to mitigate or adapt to vulnerable conditions.

The power of vulnerability analysis is that, by starting from outcomes, it avoids making assumptions about what led to the vulnerabilities. The causes of the vulnerabilities are effectively a ‘black box’, in other words, they do not need to be understood in order to take effective action. The vulnerability itself is either a known known or a known unknown. The causes of the vulnerability, on the other hand, can be unknown unknowns.

Sharing integrated modelling practices – Part 2: How to use “patterns”?

October 9, 2023June 1, 2017

By Sondoss Elsawah and Joseph Guillaume

authors_sondoss-elsawah_joseph-guillaume — 1. Sondoss Elsawah (biography)
2. Joseph Guillaume (biography)

In part 1 of our blog posts on why use patterns, we argued for making unstated, tacit knowledge about integrated modelling practices explicit by identifying patterns, which link solutions to specific problems and their context. We emphasised the importance of differentiating the underlying concept of a pattern and a pattern artefact – the specific form in which the pattern is explicitly described.

In order to actually use patterns to communicate about practices, the artefact takes on greater importance: what form could artefacts describing the patterns take, and what mechanisms and platforms are needed to first create, and then share, maintain, and update these artefacts?

While the concepts of ‘problem, solution and context’ should be discussed in some way, there is no single best way of representing patterns as artefacts. The form of artefacts will differ depending on many factors, including how the users perceive the ease of:

Sharing integrated modelling practices – Part 1: Why use “patterns”?

September 12, 2024May 30, 2017

By Sondoss Elsawah and Joseph Guillaume

How can modellers share the tacit knowledge that accumulates over years of practice?

In this blog post we introduce the concept of patterns and make the case for why patterns are a good candidate for transmitting the ‘know-how’ knowledge about modelling practices. We address the question of how to use patterns in a second blog post.

In broad terms, a pattern links a solution to a problem and its context. As a means of externalizing understanding of practices, the concept has been used productively in various fields, including architecture, computer science, and design science. For a more general introduction to patterns, see Scott Peckham’s blog post. While a “pattern” is ultimately a simple idea, there tends to be disagreement about a precise definition. This poses a problem for this blog post.

The path perspective on modelling projects

February 10, 2025March 28, 2017

By Tuomas J. Lahtinen, Joseph H. A. Guillaume, Raimo P. Hämäläinen

authors_tuomas-lahtinen_joseph-guillaume_raimo_hamalainen — 1. Tuomas J. Lahtinen (biography)
2. Joseph H. A. Guillaume (biography)
3. Raimo P. Hämäläinen (biography)

How can we identify and evaluate decision forks in a modelling project; those points where a different decision might lead to a better model?

Although modellers often follow so called best practices, it is not uncommon that a project goes astray. Sometimes we become so embedded in the work that we do not take time to stop and think through options when decision points are reached.

One way of clarifying thinking about this phenomenon is to think of the path followed. The path is the sequence of steps actually taken in developing a model or in a problem solving case. A modelling process can typically be carried out in different ways, which generate different paths that can lead to different outcomes. That is, there can be path dependence in modelling.

Making predictions under uncertainty

August 24, 2022August 25, 2016

By Joseph Guillaume

Prediction under uncertainty is typically seen as a daunting task. It conjures up images of clouded crystal balls and mysterious oracles in shadowy temples. In a modelling context, it might raise concerns about conclusions built on doubtful assumptions about the future, or about the difficulty in making sense of the many sources of uncertainty affecting highly complex models.

However, prediction under uncertainty can be made tractable depending on the type of prediction. Here I describe ways of making predictions under uncertainty for testing which conclusion is correct. Suppose, for example, that you want to predict whether objectives will be met. There are two possible conclusions – Yes and No, so prediction in this case involves testing which of these competing conclusions is plausible.