1660238357887 Dirk

Design Management: See The Positive Side Of Insecurity

June 25, 2021
Review of past decisions can show if they really were right

The Japanese company I worked for during an expansion project periodically reviewed previous decisions. While this drove the American managers nuts, I realized that it was a wonderful idea — if you have the heart for it.


During this exercise, all our past choices passed muster but that wasn’t a given. The tank layout had changed a little; operators wanted more room to make sampling easier. Revisions to the stainless steel containment made the walls taller and reduced the area to prevent tripping.

This step, which I call second-guessing a project, can create opportunities to improve it. Chances are that not everyone who might use the equipment being installed was available during project review. In addition, decisions cause ripple effects. For example, eliminating the local read-out on an instrument might save a few dollars but force an operator to rush into the control room or wait on the radio for a reading while sweating in the hot sun.

I can hear the nay-sayers now: “Anytime you give operations time to change a scope, the budget leaps out of control.” However, if you followed my advice on budget estimating by taking the highest bidder (“Processing Equipment: Pad Your Cost Estimate”), you’ll have included some fat. Spend it to make a better product. Besides, nobody will remember that you saved two hundred dollars on the local read-out; the success of your project depends on whether it works!

Second-guessing should include all phases of a project, from design to handover. These reviews also should create a list of countermeasures, i.e., plans for addressing potential problems, another idea borrowed from Japanese engineering practices. Countermeasures answer the “what-if” questions in the project. For example, how will you make up production if one of the centrifuges you’re installing goes down? Or, have you selected the right vendor if its repair facilities are much further away than those of competitors? Second-guessing means bringing up previously closed problems, examining them, and possibly discovering overlooked or forgotten questions.

To structure a review like this, use a template for a what-if hazard and operability (HAZOP) review as inspiration; I recommend “Safety and Security Review for the Process Industries: Application of HAZOP, PHA, What-If and SVA Reviews,” 4th ed., by Dennis Nolan.

Start with:
a) What happens when the power goes out?
b) What if freezing occurs?
c) How would a “once-in-a-100-year-intensity” flood affect the project?
d) How would disruptions to the supply chain impact the project? (Consider the current cut in automobile production because of chip shortages.)
e) Is the startup or shutdown clunky?
f) Is it simple to expand the project at a later date?
g) Can the equipment be turned down easily?
h) How susceptible is the project (product) to fouling or contamination?
i) Can you reduce the volume of any problematic process waste?
j) Should you use rupture discs instead of relief valves for pressure relief of some equipment (e.g., ones with viscosity issues)?
k) Are utilities adequate? (Think summer and winter, remember reliefs, vents and drains.)
l) Are the materials of construction correct and what are the choices based on (coupons or literature references)?
m) Have you properly allowed for corrosion? (Opting for a thinner wall of a more-corrosion-resistant material may seem sensible today but trading thickness for resistance may look like a dumb choice later.)
n) Does the design make it easy to insulate, replace, modify and install?
o) Is your sampling and instrumentation barely adequate (without redundancy) or excessive (swamping the control system with inputs)?
p) Are safety settings too close to operating conditions (raising the risk of alarm overloads)?
q) Are your safety countermeasures (showers, grounding, etc.) correct?

After you’ve compiled a list, send it to the stakeholders. Don’t be surprised if they ignore it.

Take a walk and ambush a few people! Walk in with a quick presentation of your project to refresh their memory. Spark their interest by asking what they think the project goals are and do they see anything that could trip up the effort. Use this process to scope out your list of potential problems. Once you’ve got the input you need, compile it into a memo; circulate it and amend your scope if needed.

About the Author

Dirk Willard | Contributing Editor

DIRK WILLARD is a Chemical Processing Contributing Editor.

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