BUSINESS AND ECONOMIC STATISTICS

BUSINESS AND ECONOMIC STATISTICS

PROJECT ASSESSMENT

Executive Summary

This report presents results from research investigating the efficiency and effectiveness of the mechanics at AllRepairs in terms of the time that they take in carrying out the repairs. In AllRepairs, a dispatcher evaluates every job lodged on the basis of how difficult it is likely to be and then assigns one of their four mechanics to the job. In this research, the Human Resources Department provided information on how long any employee has been with the company. All mechanics keep time sheets that allow data to be collected on time spent on each repair job. Data was collected from the branch of AllRepairs that provides mechanics to repair refrigerators and from by randomly selecting a sample of 293 jobs which were done last year. In order to get data on the level of satisfaction of the customers, a survey was carried out on the associated customers.

either satisfied or very satisfied with the surfaces of the mechhanics.

Introduction

AllRepairs is a firm that offers a wide range of repair services for households and businesses. Like any other business enterprise, AllRepairs needs efficient staffs who work effectively. The company has a policy of systematically reviewing all branches of their organization in order to maintain a high quality of service and to isolate any inefficiency in the provision of the various services they provide. For this particular purpose, the company contracted Dynamic Econometric Consulting Services (DECS) to evaluate the efficiency of the repair staff as measured by the time it takes them to undertake their assigned jobs. In particular, DECS was supposed to find evidence of any marked differences across staff undertaking the same tasks. In order to maintain good relationship with customers and maximize the chances of repeat jobs, AllRepairs has been engaging consultants to conduct customer satisfaction surveys in the past. From these previous surveys, the company has set 80% as the target for either satisfied or very satisfied customers. DECS was supposed to use statistical analysis to determine whether this was the case in the refrigerator repair branch.

Key Points

• The least time taken to complete a repair job was 6 minutes and the maximum was 107 minutes and the overall average time was 32.642 minutes.
• The average time for mechanic 1 was 31.36 minutes.
• The average time for mechanic 2 was 39.683 minutes.
• The average time for mechanic 3 was 32.027 minutes.
• The average time for mechanic 4 was 28.875 minutes.
• The average time for job difficulty level 1 was 20.024 minutes.
• The average time for job difficulty level 2 was 35.011 minutes.
• The average mean time for job difficulty level 3 was 51.212 minutes.

The results show that average times per job across the mechanics vary from 28.875 minutes to 39.683 minutes. The table below shows the relationship between the average time per job and the experience of the mechanic.

The chart above shows that there is a correlation between the number of years of experience of a mechanic and the average time taken to complete a job. Mechanics with more working experience in AllRepairs generally complete their repair jobs in less time than those with less experience. This implies that the more a mechanic works with the company, the more efficient he/she becomes.

From the collected data, 227 customers either said that they were satisfied or very satisfied with the way the job was done. In order to find out if our data supports 80% level of satisfied and very satisfied customers, we will let x be the proportion of the satisfied and very satisfied customers. The null hypothesis Ho: x = 0.8 is tested against the alternative hypothesis: Ha: x is not equal to 0.8.

If we take the customers who said that they were either satisfied or very satisfied to be OK and all the other customers to be NOT OK, then the variables become a binomial setting with N = 293 and x = 0.8.

x is the proportion of OK jobs in the sample of 293.

If Ho is true then the variable x will approximate normal distribution with mean = 0.8 and standard deviation = SQRT [(0.8) (0.2)/293] = 0.023.

The mean of the sample, expressed as a proportion of the total is (32.642/293) = 0.111.

If Ho is true, the associated z score is 4.807.

Testing 5% level of significance, the critical Z scores are z>2.0167and z<-2.0167 = 5.1693. We therefore accept Ho at 5% level of significance. The statistics support the 80% target set by AllRepairs Company. This implies that 80% of the customers whose refrigerators were repaired by the company’s mechanics were either very satisfied or satisfied with the service.

The diagram above shows that the most of the associate customers are satisfied with the services offered by the mechanics at AllRepairs.

The table below shows the average time (in minutes) taken by the mechanics for the different levels of job difficulty.

Mean Time (Min)

From the chart above, it is clear that the average time taken to complete a job is dependent on the level of difficulty of the job as classified by the dispatcher. Level 1 jobs have the least mean time of completion followed by level 2. Jobs of difficulty level 3 have the longest mean time for completion.

Experience and Efficiency

As mechanics gain more experience working for AllRepairs, they become more efficient and spend less time on a job.

Difficult Jobs and Experience

Less experience mechanics generally take more time on difficult jobs than the mechanics with many years of experience. This is evident from figure 3 above. The data shows that mechanic 4 who has the least experience of two years with the company has an average of 35.267 min for completion of the most difficult jobs.