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Case study is given with 12 questions to be answered afterwards on the subject of quality in construction

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Case study is given with 12 questions to be answered afterwards on the subject of quality in construction. There are both calculation and written answers required.
 

Assessment 2 – Case Study (30%)

Company Background

Bilt Co. is a civil engineering, construction and specialist minor works contractor with over 50 years in the industry. Due to national growth of the economy over the last 36 months it has seen it’s turnover increase to circa $50m, along with an increase to over 100 fulltime staff and up to 500 subcontractors at any one time. The company has developed a number of specialisms that enable them to offer a wide range of construction services including new build, fit-out, restoration and refurbishment as well as a comprehensive range of civil engineering services. Its vision is to be a specialist civil engineering and construction business, offering world-class innovation, sustainability and delivery with a ‘Local’ customer focused service. Taking ownership, creative thinking and a focused customer service enable Bilt Co., to deliver on its vision values.

 

Based in Eastern Australia, they work throughout the South East, Central, New South Wales and Melbourne focusing on the retail, commercial and industrial sectors, infrastructure, highway works, environmental management, leisure, education, public realm and mixed use development.

Company Needs

Bilt Co. does not currently implement any formally recognised and accredited management systems. Their rapid growth over the last three years has slowly been having an impact upon the quality of the products they supply and this in turn has impacted client satisfaction, both of which are a primary concern to them.

 

The organization recognised that to be a world class, innovative, sustainable, customer focused business they had to work with the best. They also wanted a more efficient way of working to save time, money and resource, improve operational performance and become a consistent performer in their sector.

 

The economy has more recently taken a sudden down turn resulting in clients demanding more at the pre-qualification stage and the ability to win work is becoming difficult, they have been advised that they need to gain quality assurance certification. In this regard Bilt Co. sought your help, ABC Consulting an Australian accredited body, in order to help them overcome these challenges.

 

At a recent meeting with you they have explained some quality issues in regard to supplier products they have received (see below); that in turn has impacted both the visual quality and possibly the structural integrity of a supplied product. This has eroded customer satisfaction and relations; they would like your feedback on the issues raised below.

Current Company Position

Bilt Co., is dedicated to proving things are done properly and with due care and attention, but this appears to be slipping, this is being attributed to the growth in size of the company.

 

Currently Quality Control (QC) appears to be undertaken by staff working reactively to undertake quality checks via inspections, and when things have failed taking corrective actions to rectify quality issues.

 

There is no clear person in charge of QC management at Bilt Co, however the team in general is very motivated and keen to change their quality practices for an improved system but they just do not know how to go about it or what is needed. Independent budget approval has been given from management for the Operations Manager to develop a dedicated team that works towards objectives related to improved quality and customer service to perform smooth enhancements without any constraints and restraining forces.

Site Quality Control

The company had recently completed a multi-storey reinforced concrete car park project where the client had alerted them to the fact that there appeared to be cracking to the soffits of a number of slabs after occupancy. Fortunately they had retained a selection of the D500N20 reinforcement bars, from the overall batch of bars used in the manufacture of the carpark slabs. The company had the reinforcement bars tested for their tensile strength (Rm), and table 1 shows the results. The Construction Director advises that the Maximum tensile strength of these bars should be ≥ 500MPa with a tolerance of +150MPa.

 

During the pouring of the concrete slabs the company ensured that they took concrete samples and had them tested for compressive strength. The Construction Director provides you with a copy of table 2 and 3 that show the 28 day compressive strength test of the concrete poured into the slabs. It appears there were 36 samples taken on two consecutive days of pouring.

 

The company are unsure if the samples tested are compliant and what does this mean for all the reinforcement and concrete used on this particular project? Does it pose a possible problem for the business?

 

 

Table 1. Tensile strength of bars

Test Sample No.               Rm

MPa       Test Sample No.               Rm

MPa

1              495         16           500

2              487         17           487

3              505         18           507

4              510         19           504

5              505         20           509

6              515         21           478

7              502         22           484

8              492         23           492

9              501         24           496

10           489         25           500

11           507         26           507

12           475         27           497

13           487         28           487

14           492         29           490

15           507         30           478

 

 

 

Table 2

Day 1

Concrete Samples                           Table 3

Day 2

Concrete Samples

Sample

No.         Strength

(N/mm2)                             Sample

No.         Strength

(N/mm2)

1              20                           1              28

2              23                           2              30

3              26                           3              30

4              30                           4              30

5              30                           5              30

6              32                           6              32

7              33                           7              30

8              35                           8              32

9              29                           9              30

10           33                           10           28

11           22                           11           30

12           23                           12           30

13           26                           13           30

14           30                           14           30

15           30                           15           32

16           32                           16           30

17           33                           17           32

18           35                           18           30

19           29                           19           28

20           40                           20           30

21           22                           21           30

22           23                           22           32

23           26                           23           30

24           30                           24           32

25           30                           25           30

26           32                           26           28

27           33                           27           30

28           35                           28           30

29           39                           29           28

30           39                           30           30

31           29                           31           30

32           29                           32           30

33           32                           33           30

34           29                           34           32

35           32                           35           30

36           26                           36           28

Questions to be answered

You know that by applying statistics to the information the data can be analysed. Back at the office you give the data to one of your employees and ask them to undertake the following tasks:

 

1.            For data contained in tables 1, 2 & 3 - find the:

a.            Mean;

b.            Mode;

c.             Median; 

d.            Variance; and

e.            Standard deviation.

 

Use the following table to insert your answers.

Table 1  Mean   

                Mode   

                Median

                Variance             

                SD          

Table 2  Mean   

                Mode   

                Median

                Variance             

                SD          

Table 3  Mean   

                Mode   

                Median

                Variance             

                SD          

 

 

2.            For data contained in table 1:

a.            Draw a control chart and identify the upper and lower control limits; and

b.            Identify which samples have failed for the 30 samples taken.

 

3.            For tables 2 and 3 draw a frequency chart (use excel to aid you).

 

4.            What comparative information can you gather from the frequency charts (previous question 3) with regard to the strength of the concrete?

a.            Discuss about any similarities and differences that you find in your results here.

 

 

Bilt Co. were recently contracted to undertake the supply and install of concrete to a large gas fired power station. The concrete pour ran continuously for 24 hours a day over a five day period. They sought the advice of your company in regard to what data they needed to collect as part of their road to improvement on quality assurance.

 

You advised that the company to undertake the random collection of concrete cube tests in batches of 36, and over the 5 day pour period to repeat this process 100 times. Your company organised the collection and storage of each batch of 36 cubes, and once cured arranged the compressive test of each batch.

 

From these tests samples you were able to derive a mean compressive strength for each batch of 36 cubes. At the end of sampling the 100 batches your organisation had developed 100 mean’s and this resulted in an overall mean of 45Kpa and you were able to calculate that the standard deviation was 1.1Kpa.

 

You once again tasked one of your employees to produce the following:

 

5.            Calculate the mean and standard deviation in the population.

 

6.            Provide the normal distribution graph for both population and sample data, showing the mean, and 3 standard deviations, you ask them to ensure they use correct symbols for population and sample.

 

7.            If we were to take a random of 16 cube tests from the population of concrete supplied, what is the probability that the mean of these 16 cubes is:

a.            Between 40 and 50;

b.            More than 53; and

c.             Less than 32.

 

 

While the above data is being statistically analysed you set about answering the following questions:

 

8.            Bilt Co. are going to tender for the upgrade to 5Km of road section. The QM wants to ensure that there is enough money allowed in the tender budget to adequately undertake the QM process on this project if successfully tendered. In relation to the bituminous materials supplied for the road surface explain to the tender manager the following:

a.            The difference between population and sample?

b.            Why sampling needs to be undertaken?

c.             The different types of statistical sampling methods and which you are advocating to use with an explanation as to why?

 

 

9.            By using the given information about Bilt Co., explain which type of quality methods are currently implemented in Bilt Co. and what are the pros and cons of using it?

 

10.          What key person would the Construction Director need to employ to spearhead a change to TQM?

 

11.          You recognise that the functional role above is a must requirement, and TQM implementation would be a project, the first steps would be to create a dedicated team to implement TQM smoothly, can you explain:

a.            List what steps are involved in the creation of a team?

b.            Why does this new person need to consider culture when selecting the team members and how will this affect the selection of individuals that make up the team?

 

12.          Bilt Co. has 500 sub-contractors that are very crucial in maintaining its business portfolio to be profitable, please explain:

a.            How many types of sourcing are available and,

b.            What factors need to be considered as part of partnership agreements?

 

 

 

 

 

 

 

 

Assessment Guidance  

Assessment Format, Layout and Submission

Your assignment must be produced as:

•             Word document, using Calibri font size 12, 1.5 line spacing, and

•             3.0cm margins all round.

•             Each page must have a footer that includes page numbers and your name and student number, right justified.

•             Use Chicago referencing.

•             Include correct in?text citations and provide a separate list of references.

•             File naming (use this for submitting your assignment)–

o             Your Last name, Your First name, Your Student ID, Assessment 2,

o             Place an underscore _ between each of the above no space, no commas.

 

Your report must be structured as follows:

•             Title Page

•             Table of Contents

•             Answers in numerical order.

•             Reference List

 

Points to Note:

•             The Word document file must be submitted through the correct Turnitin link by the due date.

 

•             Late penalties will be applied in accordance with the details within the unit outline where one or both submissions are not submitted by the due date and time.

 

•             As always all source material MUST be acknowledged and any form of plagiarism will be dealt with accordingly.  Referencing should be in Chicago style as per the details in the Unit Outline.

•             This assessment will be assessed in part using the proficiency guide for report writing as per university guidelines for this level of study.

 

Marking Criteria