LSSBB Sample Questions & Answers

This is the best goal statement because it follows the SMART (Specific, Measurable, Achievable, Relevant, Time-bound) criteria. It clearly defines the metric ('door-to-doctor' time), specifies the process segment (non-critical patients), provides a measurable baseline (75 mins) and target (45 mins), sets a deadline (end of Q3), and includes a constraint (without impacting outcomes). The other options are too vague, lack metrics, or describe the problem rather than the goal.

The Kruskal-Wallis test is the correct choice. It is the non-parametric equivalent of the One-Way ANOVA and is used to compare the medians of three or more independent groups when the data does not meet the normality assumption. One-Way ANOVA requires normally distributed data. The Mann-Whitney U test is used for comparing only two groups. The Chi-Squared test is used for categorical data, not ordinal rating data.

A U Chart is the most appropriate choice. It is used to monitor the average number of defects per unit (in this case, dropped calls per call) when the sample size (total number of calls) varies over time. A C Chart is used for the number of defects when the sample size is constant. P and NP charts are for tracking the proportion or number of defective units, not the number of defects within a unit or opportunity area.

This interpretation is correct. The coefficient 2.5 indicates that for each one-unit (dollar) increase in Ad Spend, Website Visits increase by 2.5 on average. The p-value of 0.002 is less than the typical alpha level of 0.05, indicating that the relationship is statistically significant. The R-squared value of 0.75 means that 75% of the variation in website visits is explained by the ad spend, suggesting a strong model fit. The other options misinterpret the statistical outputs.

The most appropriate action is to prioritize this failure mode due to its high Severity rating (7), especially since it impacts customer safety. While RPN is a useful tool for prioritization, it should not be used as a rigid, absolute threshold. High Severity ratings, particularly those related to safety or critical regulations, must always be addressed, even if the overall RPN is below a predefined cut-off. Modern FMEA practices (like AIAG-VDA FMEA) emphasize prioritizing high Severity first, then Occurrence, then Detection, rather than relying solely on the RPN.

A SIPOC (Suppliers, Inputs, Process, Outputs, Customers) diagram is the most suitable tool. It provides a high-level, bird's-eye view of the process, its boundaries, and its key stakeholders (Suppliers and Customers) without getting into excessive detail. This makes it ideal for the early stages of the Define phase to establish scope and context. A detailed VSM or swimlane map would be created later, typically in the Measure phase, once the high-level process is understood.

The scenario where the effect of one factor depends on the level of another is the definition of an interaction effect. To evaluate this, the team must use a design that is not only capable of estimating main effects but also the interactions between factors, such as a full factorial or a high-resolution fractional factorial design. Replication helps estimate error, confounding is the mixing of effects (usually to be avoided), and blocking handles nuisance factors.

The Xbar and R (Range) chart is the standard choice for monitoring variable data (like weight) collected in subgroups of a constant size (n=5). The Xbar chart tracks the process average (central tendency) between subgroups, while the R chart tracks the process variation (dispersion) within the subgroups. I-MR charts are for individual data points (subgroup size of 1). P and NP charts are for attribute data (e.g., pass/fail).

The Mann-Whitney test (also known as the Wilcoxon rank-sum test) is the correct choice. It is the non-parametric alternative to the 2-sample t-test and is used to compare the medians of two independent groups when the data is not normally distributed. Since the data failed the normality test and the samples are from two different departments (independent), this is the appropriate test. A 2-sample t-test requires normality. A paired t-test would be used if the samples were related (e.g., before-and-after measurements on the same items). ANOVA is for three or more groups.

This solution is the most effective because it systematically addresses all three identified root causes using a combination of Lean tools. Optimizing picking routes addresses cause #1. A Kanban system directly solves the packing material shortage issue (cause #2). Implementing barcode scanners serves as a mistake-proofing (Poka-Yoke) device to reduce verification errors (cause #3). The 5S program provides a foundation for maintaining an efficient workspace. This approach is practical, targets the specific problems identified, and aligns with Lean principles of waste reduction and flow improvement, making it superior to a costly, high-risk automation project or a solution that only focuses on worker performance without fixing the underlying system issues.