Decision Gates and Cookies

Published:

By Jeff MacKinnon, P.Eng., PE

Something that I seem to continue to have to explain to clients is the importance of having a good decision process so that when a decision is made its understood that changing it will have a lot of ripple affect and will effect budget and schedule.

That doesn't mean that changes can't happen, just that there needs to be a process that has points of no return. In the industry they are sometimes called decision gates.

Once the project goes through this gate they can't go back without impact to the budget, scope and/or schedule.

For overall project phases from the owner/client perspective every project has 5 phases, starting at Phase 0.

Cookies to the rescue

If this isn't something you have experienced an analogy may be baking cookies.

In the initial project development phase, where the company or developer sees a need to improve their business this is called the business development and front end engineering design stage.

For this analogy the results of this process are that you need cookies, you want them home baked and they are going to have chocolate chips.

Lets start the process.

Phase 0 - Deciding the Standard

In Phase 0 we start looking through cookbooks and someone in the house would like them to be a bit healthier, Dad is on a health kick and wants to make sure they are full of nutrients. Also grandparents are coming over this weekend so we should make sure that there are lots of them.

The major design requirements are decided:

  • chocolate chip cookies with,
  • nuts and,
  • at least 3 dozen.

Phase 1 - Schematic Design

Next we need to decide on now the baking process is going to work.

Do we have space to make the ingredients? (general arrangement) Do we have nuts in the house? (major/special equipment) Do we have the recipe? How fancy are these cookies? (process flow)

We decide that the cookies are going to be simple, not back of the chocolate chip bag simple, but not 15 step with a 48h chill of the dough and browned butter either.

We also have nuts in the cupboard so we don't have to make any special trips to the store to get these cookies made.

Phase 2 - Detailed Design

We dig out a couple cooking books that are gathering dust above the fridge and find a few great options that meet all the requirements from Phases 0 and 1.

We make sure everyone in the house (the stakeholders) agree on the recipe and we are ready to start baking (construction).

Phase 3 - Baking/Construction

The recipe starts with creaming the butter and sugars, then in a separate bowl add the dry ingredients (except the chips and nuts).

Next we mix the dry ingredients into the creamed butter.

Finally we start stirring in the chips and nuts.

At this moment Dad gets off a phone call and decides that he would like to give some of these cookies to his friend, but he's allergic to nuts, so the cookies can't have nuts in them.

You can't go back

So at this point we have already passed through 3 decision gates and during this entire process nuts were a decided scope for the project.

They can't be removed now, the design relied on the nuts, and since construction, I mean baking, already started we will have to go back to Phase 2 to re-design the recipe (for cookies its just removing the nuts afterall) and start the baking process again.

This late decision affects:

  • the timeline, the baking takes longer;
  • the budget, we need more ingredients
  • maybe quality, the recipe we chose may be best with nuts so we need to either find a different one or have inferior cookies.

Back to Electrical design

The types of decisions that are made during the design process have implications down stream from the project. Sometimes this is easy like deciding on an equipment vendor that has specific advantages over others and building a design around it, or maybe its something less obvious like changing the control voltage from 24Vdc to 125Vdc because that's what the breaker vendor recommends, but all the relay contacts need to be changed out for that breaking voltage.

In this specific cookie case, removing the nuts is like removing a custom feature of the design. A feature that was prominent very early in the project, and then was relied on throughout the entire design. Removing it may appear to make the entire project "simplier" but it will also require starting some parts of the design from scratch, all the way from Phase 0 through to where we left off at Phase 3.

What about Phase 4?

In this cookie example we didn't get to Phase 4, but this is where the baker gets to taste their cookies and confirm that they are as tasty as they expected.

I hope this helps explain why its important to have that process. I prefer to be involved with a project at the very beginning, when the client just had that shower thought and wonders if its a good idea or not. That is rarely the case, but it really helps prune ideas to a few options that can be further developed in development phases so the options are clear moving into Phase 0.