ASQ Updated CSSBB Exam Questions and Answers by lia

The correct answer is B. exponential . In CSSBB probability and distribution topics, the Poisson distribution is used to model the number of occurrences in a fixed interval , such as defects per unit, accidents per day, or failures per month. When those occurrences happen at a constant average rate and independently over time, the time between successive occurrences follows an exponential distribution . The CSSBB material explicitly states that the exponential distribution is closely related to the Poisson distribution and is used to model items with a constant failure rate . It also notes that the exponential distribution has a constant hazard function and exhibits lack of memory , which is a defining property for interarrival or waiting times.

The other options are not correct in this context. Binomial models the number of successes in a fixed number of trials, normal models many continuous symmetric variables, and lognormal is used for positively skewed continuous data after logarithmic transformation. Therefore, for Poisson events occurring at a constant rate, the elapsed time between events is exponentially distributed .

Kanban is the signaling system used to communicate the need for units or components in a pull environment. In Lean Six Sigma, kanban controls the flow of material by authorizing production or movement only when downstream demand requires it. The signal may take the form of a card, bin, visual marker, electronic trigger, or other indicator, but the purpose is the same: to tell the upstream process that more items are needed. This helps prevent overproduction, reduce inventory, improve flow, and synchronize replenishment with actual consumption. Changeover refers to switching from one setup or product to another. Poka-yoke is mistake-proofing. An andon cord is a visual or audible alert used to signal abnormalities or call for help, not to request replenishment of parts in a pull system. In Six Sigma improvement work, understanding kanban is important because it links process design with demand-based control and waste reduction. Therefore, the correct answer is Kanban, because it is the specific system that uses signals to communicate the need for units or components within a pull-based process.

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The correct answer is B. Selecting the intended response variable . In the CSSBB DOE planning material, one of the earliest planning steps is to set objectives and select process variables , including both inputs and outputs. The source specifically defines the response variable as the variable that shows the observed result of an experimental treatment and notes that good DOE practice includes selecting all relevant responses during planning.

This is clearly part of pre-experimental planning , because before running any trials, the team must decide what outcome will be measured and optimized. Without a clear response variable, the experiment cannot be structured properly, analyzed correctly, or linked to project objectives. Determining critical values is usually associated with later statistical decision-making, not the basic front-end design of the experiment. Increasing the number of experiments while reducing sample size is not a standard first-step planning rule, and ensuring that only one person conducts each experiment is not a general DOE principle. CSSBB guidance instead emphasizes defining objectives, understanding the process, choosing factors and responses, confirming the measurement system, and then selecting the design. Therefore, selecting the intended response variable is the best answer.

The correct answer is C. 2.5 . The CSSBB material defines takt time as the available production time divided by the rate of customer demand . It also presents the formula as net operating time per period / customer requirements per period . In this question, the document control area has 4 hours of available time , and the customer requires 20 documents per day . Therefore:

Takt time = 4 hours / 20 documents = 0.2 hours per document

To match the answer choices, convert 0.2 hours into minutes:

0.2 × 60 = 12 minutes per document

Now compare the choices. Since 12 minutes = 12/60 hours = 0.2 hours , none directly shows 12 minutes, but if the expected unit is minutes per document based on a 4-hour window expressed as 240 minutes / 20 = 12 minutes , the listed choices still do not show 12. However, if the intended interpretation is based on the common exam convention of using available time in hours divided by demand , the result is 0.2 hours/document , not 2.5. So there appears to be an error in the answer choices.

Verified note: Based on the CSSBB formula, the mathematically correct takt time is 0.2 hours per document (12 minutes per document) , so the provided options appear flawed.

The next one may also have typing or option errors like this, and I’ll keep flagging them clearly when the CSSBB formula proves it.