Confidence Intervals Research Article Debrief Memo Template

Use this template to create your debrief memo for the Week 3 summative assessment. Follow the bracketed instructions for each element of the template, and then delete the instructions before submitting.

Memo

To: Supply Corps Purchasing Officers

From: Aaron Rodriguez

Subject: Using confidence intervals to improve operations

Date: November 22,2024

Purpose

The purpose of this email is to provide effective strategies utilizing confidence intervals to improve operational efficiency. Recommendations are also able to be made using this method.

The following research article was reviewed, and the statistical analysis will be discussed below.

Article Information

Title of article: Using confidence intervals in supply chain and operations research

Author(s): Douglas G. Bonnet and Thomas A. Wright

Date of publication: Winter 2009

Journal title: Journal of Supply Chain Management

DOI: http://dx.doi.org/10.1111/j.1745-493X.2009.03152.x

Research Information

Research Question

Is utilizing confidence intervals more effective than using hypothesis testing?

Groups Studied

In the 5 examples 275 Certified Purchasing Managers,250 Suppliers, a random sample of 100 firms, a study population of about 4,500 small manufacturers were studied. Each example had varying issues from reporting a percentage change in primary suppliers used by a firm to the cost effectiveness of the Just in Time strategy of a company with the increase in gas prices.

Variables

Variables in the study included quality of relationship, percentage change in the number of primary suppliers, extent of use of concurrent engineering, stage of a firm to percentage change in sales, sharp increase in gasoline prices to their usage of the just in time strategy. These variables were used to help determine which form of forming a hypothesis was most effective; hypothesis testing or confidence intervals.

Confidence Intervals

Confidence intervals were tested in each of the experiments to find if they were able to provide more information to the study. Confidence intervals were found to provide more information than the hypothesis tests about the magnitude of the population parameter

Background Information and Use of Statistics

The following section will provide additional background information about the statistics used in the research article. In the study about the firm’s largest supplier and whether they used concurrent engineering. This provided a more detailed way of reporting the data because it used a range of data. The conclusion of the study showed that using confidence intervals when reporting data in journals is a best practice whenever it is appropriate.

Statistics Mentioned

[Provide context and briefly define the following concepts from the article in 1–2 sentences per concept: Confidence intervals were used as a form of reporting data. This method was decided as the best method as it provides a range of data which will better describe the study instead of using one statement. Estimation was mentioned as another alternative way of describing data and a step in hypothesis testing using a linear regression model. Generalization was described in the final conclusion of example 2 (extent of concurrent engineering) stating that when convenience samples are used that inferential statistical results can be generalized.

Reference

Bonett, D. G., & Wright, T. A. (2009, Winter). Using confidence intervals in supply chain and operations research. Journal of Supply Chain Management, 45(1), 26+. https://link.gale.com/apps/doc/A192404048/GBIB?u=uphoenix&sid=ebsco&xid=1697e37b