SPC Assumptions

Introduction

Statistical Process Controls (SPC) is a suite of methods that can be employed to control a manufacturing or assembly process. It has a wide range of potential applications ranging from consumer products to defense. It can be employed at the lowest element of component manufacturing or an assembly operation.

This article discusses the assumptions necessary to understand SPC.

Fundamental Assumptions

The process is stable and in control.
The data are independent of each other.
The data of each subgroup are identically distributed.
Real valued data are approximately normally distributed and counting data may be approximated by the normal distribution.
A measurement can occur in only one subgroup, i.e., sampling without replacement.

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by Perry Parendo Leave a Comment

Set Up of New Equipment

Many times, new equipment does not move smoothly onto the production floor. Eventually, operations will say “just get it out here.” Using our methodology, we have helped companies be in a position where they are telling us to wait to install it! When you can understand the equipment up front, it makes a huge impact. How do you fit on the spectrum? [Read more…]

by Doug Plucknette 1 Comment

Reliability Centered Maintenance – Common Questions

When is the best time to do an RCM analysis on your equipment?

While RCM Blitz™ can be applied at any time in the asset lifecycle, the best time to do an RCM analysis is in the design phase of a capital project. Reliability Centered Design is much more than a thorough RCM analysis on a critical asset, it also uses [Read more…]

by Robert Allen Leave a Comment

Is a Task a Deliverable?

Tasks (or action items) are a fundamental building block of an ongoing work-effort or project schedule. While we tend to think of completed actions as deliverables, a project schedule can also be considered a project deliverable….and the value of well-written task (within the schedule or otherwise) is often overlooked.

Generally, a task begins with a verb (some action to be performed) to achieve a milestone or outcome to some desired level of completion. (Recall a previous related article where we discussed the “definition of done”.)

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by Greg Hutchins Leave a Comment

Was BP’s Catastrophe in the Gulf a Defining Moment for the Oil Industry?

Guest Post by Geary Sikich (first posted on CERM ® RISK INSIGHTS – reposted here with permission)

1. Introduction

The BP Deepwater Horizon catastrophe cast a shadow on the oil industry and its senior executives. Has the industry learned its lessons or will it be forced to repeat the same mistakes over and over again? Oil company executives and board members should have seen the Deepwater Horizon event is as a wake-up call for the industry. [Read more…]

by Mike Sondalini Leave a Comment

Pump Life Extension — The Impeller

A spinning pump impeller provides the means to draw incoming product through the pump, energise it, and then force it out under pressure. The impeller coverts the electrical energy from the motor into hydraulic energy of the liquid. It does this by taking the liquid into the center of the impeller and flinging it outward at high speed. To efficiently continue to do this the impeller must remain in the same condition as it was when first installed. If the impeller deteriorates the conversion from electrical to hydraulic energy becomes inefficient. Power is wasted, flow and pressure fall and the pump cannot do its designed duty. [Read more…]

by Dennis Craggs Leave a Comment

Common and Special Causes of Variation

Introduction

Quality Costs for manufacturing or services can be categorized as prevention and appraisal costs, and internal and external failure costs. Control occur in prevention and appraisal activities, both of which rely on data. However, when data is collected, it shows variation. One must understand variation to know how to react.

Dr. Deming indicated that 94% of variation is from common causes and about 6% is from special causes. So what are the common and special causes of variation?
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by Perry Parendo Leave a Comment

Valuable Risk Management

While a potentially useful technique, Risk management is often an unwanted obligation. Done well, it can prevent field failures and gain needed resources. Does your project or organization get this value? Or do you only experience the pain? [Read more…]

by Greg Hutchins Leave a Comment

Entering a New Market Gone Wrong

Guest Post by John Ayers (first posted on CERM ® RISK INSIGHTS – reposted here with permission)

This risk story includes risk at the enterprise level, the program/project level, and the product level. From the enterprise level risk, it was a little naïve on my company’s part to think they could go from zero not having manufactured any sonobuoys previously) to full up production the first time around without investing the time and finances to go up the learning curve prior to making the bid. From the program/product level risk viewpoint, the baseline plan did not include sufficient component and subassembly trial builds and testing before finalizing the concept, preliminary design and final design. [Read more…]

by Mike Sondalini Leave a Comment

Equipment Criticality

How do you decide what level and type of maintenance to use on an individual item of plant and its sub-assemblies? Not all equipment is equally important to your business. Some are critical to production and without them the process stops. Others are important and will eventually affect production if they cannot be returned to service in time. While other items of plant are not important at all and can fail and not affect production for a very long time. [Read more…]

by Dennis Craggs Leave a Comment

Quality Costs

Introduction

Businesses, to be competitive, need to control all costs. Product or service failure can result in large uncontrolled costs. As product development proceeds, the cost of failures increases. The concept is shown in figure 1.

Figure 1

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by Perry Parendo Leave a Comment

No Wasted Motion

A coaching philosophy involves a concept we call “no wasted motion.” It looks at the fundamentals and the impact of various decisions. Habits create results in business and in basketball. A critical and yet realistic eye can help you achieve at the next highest level. [Read more…]

by Doug Plucknette Leave a Comment

How To Create An Environment of Innovation

I found myself seated next to a corporate executive in a recent flight out of Atlanta, while I was attempting to read a book, he was yammering away on his cell phone about quarterly results and the need for a reduction in head count. Hearing this, my hopes of becoming engrossed in a good book was now over. Now I’m just upset at how some folks seem to make life changing decisions with such little regard or emotion. [Read more…]

by Adam Bahret 2 Comments

Why?

When something is working it is easy to just keep going forward. But how do you know things will keep chugging along? Is it worth stopping and asking “Why is this going well?”

I like lock picking “Lock Sport.” Of course I do. It’s a mechanical puzzle. It can also make you look like James Bond when someone forget’s their keys. I continue to challenge myself by getting progressively harder and harder locks. Throughout the years lock designs have come up with some great features to resist being picked. But there is still not one out there that is “pick proof”, so there is always a next level. I would say I am a mid-intermediate in the world of Lock Sport. So any lock that actually has good picking defenses can give me a good struggle.

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by Greg Hutchins Leave a Comment

Political Risk and Enterprise Risk Management

Guest Post by James Kline (first posted on CERM ® RISK INSIGHTS – reposted here with permission)

Former Secretary of State Condoleezza Rice PhD. and Amy B. Zegart PhD. have written a book called Political Risk: How Businesses and Organizations Can Anticipate Global Insecurity. It has received good reviews. Having read the book, I would concur. It is an important book for those concerned with the increasing volatility and associated risk of the global economy. This piece discusses the relationship between Political Risk and Enterprise Risk Management (ERM). [Read more…]

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