# What is QC chart?

## What is QC chart?

A quality control chart is a graphical representation of whether a firm’s products or processes are meeting their intended specifications. If problems appear to arise, the quality control chart can be used to identify the degree by which they vary from those specifications and help in error correction.

**What is a QC value?**

These values provide meaningful information about method performance within the laboratory under stable conditions. The ultimate goal of establishing QC values is to collect as much information as possible about the control material before starting to utilize it to monitor the performance of a particular method.

### What are QC results?

QC gives the laboratory confidence that test results are accurate and reliable before patient results are reported. This module explains how quality control methods are applied to quantitative laboratory examinations. Quantitative tests measure the quantity of a substance in a sample, yielding a numeric result.

**How is Levey Jennings calculated?**

Levey–Jennings charts To calculate 3 SDs, multiply the SD by 3, then add and subtract each result from the mean. For any given data point, 68.3% of values will fall between + 1 SD, 95.5% between ±2 SD and 99.7% between + 3 SD of the mean.

## In what axis of the Levey Jennings graph do you plot the calculated mean in a QC run?

Y-axis

The common method for this graphing is the use of Levey– Jennings charts. The control values are plotted on the Y-axis and date/time along the X-axis. The chart should be marked with the mean and one, two and three standard deviations above and below the mean value for easy interpretation.

**What are the 4 types of quality control?**

No. | Description |
---|---|

1 | Process control |

2 | Control charts |

3 | Product quality control, |

4 | Process control |

### How is QC range calculated?

Calculate the new control range by using the new mean with the SD determined by the equation (SD = CVh /100 X Mean). The number of SDs on either side of the mean can vary, but in many laboratories the QC range will be +/- 2 SD of the mean.

**What are the four types of quality control?**

## What are the 3 main objectives of quality control?

3 main objectives of quality control: enhance product quality and reduce risks, gain production efficiencies, and garner customer loyalty.

**How do I make a Levey Jennings chart?**

Here are the steps to create a Levey Jennings Chart using QI Macros: Click and drag over your data to select it. Next, click on the QI Macros menu > Control Charts (SPC) > Special (CUSUM, EWMA) and then on the type of Levey Jennings Chart you want.

### How many Westgard rules are there?

The well-known Westgard multirule QC procedure uses 5 different control rules to judge the acceptability of an analytical run.

**What is the difference between Levey Jennings and Levey-Jennings control chart?**

One difference is the way that control limits are calculated. The Levey-Jennings chart uses the calculated standard deviation (or a known standard deviation) to determine the control limits. The individuals control chart uses an estimated standard deviation from the range chart to determine the control limits.

## How can I plot the results of the Levey-Jennings QC practice exercise?

Plot these results, one from Control 1 and one from Control 2, for each day. You can print the Levey-Jennings QC Practice Exercise (below) to obtain a worksheet that shows all these control results. For day 1, the value for Control 1 is 200 and Control 2 is 247.

**How do you calculate standard deviation on a Levey-Jennings chart?**

Calculate the standard deviation (if a known standard deviation is not being used): You can easily calculate this in Excel using the STDEV function. 9. Calculate the upper control limit (UCL) and the lower control limit (LCL). 10. Plot the center line as a sold line on the Levey-Jennings chart and label.