He was sharp, ruthless and scary. No one wanted to meet him. But since he was the boss of our consulting firm, we had no choice but to bring the design drawings to him for his review. The usual encounters with him lasted only a few minutes. If you took any drawing to him, within minutes, he would find 3-4 blunder mistakes, make you realize how dumb you’re and throw you out of the room. That was his way of drilling perfection.

Over time, as young engineers, we learned to check and recheck the design drawings before daring to enter his room. This was the late nineties.

Two decades later…

Around 2019-2020, while doing a pharma project, I happened to be in the “boss seat.” Being the HVAC Lead from the client side, now people were bringing HVAC design drawings to me for my review. Like my old boss, I had no trouble finding a few design gaps/areas of improvement in any drawings I saw. Next week, the design team would present revised drawings incorporating the fixes from the previous week. But unfortunately, this time, I would see a few more things to fix. And the process of “comments-revise-more comments–revise again” continued week after week until one day, I realized we had fallen into the classic drip-drip approach that is so prevalent in the construction industry.

This approach has two sets of players: On one side are the originators of design drawings and on the other are the reviewers. Originators can be an engineering design company or a sub-contractor. Reviewers are usually the main contractor personnel and client representatives.

The game starts with the originator dutifully submitting a set of design drawings for review. On the other side, under the pressure of multiple priorities, reviewers would first ignore the drawings for a few days. Then, under schedule pressure, someone would do a quick review and throw them back to the originator. A week or two later, the revised drawings would return (with fixes for the previous comments), but this time, the reviewer would find some new problems. And the review story continues without any conclusion.

This is a classic drip-drip way of reviewing the design. Following this approach, the reviewers normally do not review drawings from all possible angles in one go; it’s always a quick and partial review.

The drip-drip approach is very time-consuming and frustrating for all parties. It never eliminates all the gaps in the design that come to haunt the project later.

In our project, we decided to do away with the drip-drip approach and try a simple fix: use a checklist. We decided:

• We (I and the design team) will jointly prepare a checklist of all the items that should be checked in a design drawing.
• The design team would check the drawings using the checklist before submitting them for my review.

Going ahead, we prepared comprehensive checklists for all the design drawings we were supposed to review: AHU zoning drawing, pressure layouts and AFIDs. These checklists included everything from seemingly trivial stuff like drawing title, number and revision no. to more consequential items like equipment capacities, air quantities, instruments, control schemes, etc. The AFID checklist included 60+ items to check.

I must say that initially, the design team was skeptical and felt it would waste their time. But once on board, they found it useful. As we started using the checklists, the problem of missing something in the drawings and discovering it accidentally later reduced dramatically. In the end, we all had a common feeling….we did all that was humanly possible to eliminate stupid and intelligent design mistakes and improve the design quality. This peace of mind was worth the effort.

Regardless of our experience and the white hair on our heads, checking any design is not an easy exercise for three reasons:

• Complexity: A design contains layers and layers of inter-connected information: User requirements, assumptions, industry practices, constraints, calculations, equipment selections, etc. A thorough review requires diving into the different dimensions of the design and seeing the interconnections.
• Limited and jumping mind: Neither our mind can remember 50-60 items nor it can think in a perfect sequence. If you show the same drawing to a very experienced person on two different occasions, chances are the quality and quantity of the comments would be different.
• Time constraints: Today’s projects are all rush-rush. Under time constraints, we tend to take shortcuts, which is the key reason for design gaps slipping by and surfacing during commissioning when it is much costlier to fix.

If you want to minimize design gaps and improve the overall design quality, create a simple checklist of items that should be checked in a design drawing. This initial investment (a couple of hours) will pay off handsomely.

The checklist approach works not only for reviewing design drawings but also for anything long, important and complex: Basis of Design, long reports, functional design specifications, validation master plan, test protocols, proposals, equipment selections, etc.

Why does it work? Because it overcomes the limitations of our own minds that can’t remember all things to check at one point in time.

What’s the biggest catch in the checklist approach?

Well, a checklist is just a tool whose value depends on how we employ it. What matters is…intention. If our intention is to ensure high-quality design, it’s a great tool, but if our intention is to simply fill the damn checklist for the sake of filling it, no one can help. In the end…all that counts is “intention”—not the checklist. A checklist is a means to an end–not the end.

Going back to the late nineties, I wish I had the wisdom to create a checklist to suit my boss’ requirements and avoid embarrassing encounters with him.

Finally, here is a sample checklist to give you a taste of it…

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