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Existing  production  planning  and  control  system

Chapter  3   Literature  Review

3.2   Towards  an  appropriate  construction  management  approach  in  refurbishment  projects

4.2.2   Empirical  studies

4.2.2.1   Empirical  study  1  –  Refurbishment  of  houses

4.2.2.1.2   Existing  production  planning  and  control  system

This section sheds light on the production planning and control system utilised by a

construction company for managing refurbishments in the context of a housing association.

The scheme examined in this study comprises the renovation of kitchens in three different houses. It refers to the installation of new furniture (new kitchen units and the replacement of worktops and sink tops), flooring, wall ceramic tiling, gas and water pipes, electrical wiring and cables, and decoration (wall paper and painting). It is worth mentioning that apart from the data presented in Table 16, which contains records from two contractors (here named as A and B), all information provided in this section refers to the process conducted by contractor A, contractor B contributed to the initial phases of the study but became unavailable throughout the development of the research.

The production planning and control process starts with the list of properties provided by the housing association. This list contains the number of houses subject to refurbishment during the year. Based on that, the project manager who works for the contractor sets a plan that takes into account the geographical location of the houses and the scope of works related to each of them. The output from this first analysis is a master plan containing the number and sequence of refurbishment schemes that will be undertaken throughout the year. On average, the number of houses within a scheme ranges from 5 to 20 houses. In some cases this number can go up to 50 properties, but there are also cases when the contractor has to go to some areas to refurbish just four, two, or even one house. The next step is the development of production plans for each refurbishment scheme.

The basic organisational structure deployed by the contractor to manage the construction phase of refurbishment schemes involves a project manager, a site manager, a tenant liaison officer (TLO), a foreman, and the operatives. In the refurbishment of kitchens, the contractor is in charge of executing rip out (i.e. removing kitchen units, tiles, and flooring), plastering, kitchen’s fitting, and snagging. Subcontracted services include: strip out (i.e.

removing wall paper), plumbing and electrical systems, wall tilling, flooring, and decoration.

Table 16 presents parameters used for production planning and control of a refurbishment of a single kitchen and indicates the items of work conducted along with their respective

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cycle times. Also, the last column of the table indicates the day in which each task is performed during the execution of the refurbishment.

Table 16 - Planning parameters for the refurbishment of a kitchen

Contractor A Contractor B

Item Item of work

Cycle time

(hours) Day Item of work

Cycle time

(hours) Day

1 Rip Out & Strip Out 2 1 Strip Out 4 1

2 Plumbing 2 1 1st fix electrics 8 2

3 Electrics 7 2 Plastering 4 3

4 Plastering 7 3 Fit kitchen & Plumbing 8 4

5 Fit kitchen 6 4 Tile kitchen 4 5

6 Tile kitchen 4 5 2nd fix electrics 2 6

7 Screed floor (dry time) 1 (2) 6 Decoration 1st phase (dry

time) 4 (4) 7

8 Lay floor 2 7 Decoration 2nd phase 4 8

9 Decoration 1st phase (dry time)

4 (4) 8 Screed floor (dry time) 2 (4) 9

10 Decoration 2nd phase 8 9 Lay floor 4 10

11 Handover (snagging &

cleaning)

8 10 Handover (snagging &

cleaning)

2 11

As shown in Table 16, the refurbishment of a kitchen is planned to take ten and eleven working days for contractor A and B, respectively. However, the contractors normally inform tenants that the works are going to take 15 days. This buffer is added to cope with any unforeseen situations that might disrupt works on site. Also, it is possible to note that contractors consider in their planning partial days of work. According to them, this happens mainly because of the uncertain nature of the refurbishment work that makes it difficult to have a perfect synchronization of trades on site.

According to the site manager (contractor A), the company normally finishes works within the 10 days as planned. This was confirmed during the observations carried out on site when the researcher had a chance to observe the refurbishment of three kitchens (K1, K2, and K3). Two houses (K1 and K3) were occupied during the refurbishment and one (K2) was unoccupied. Eight hours (480 minutes) is the maximum period of time available for working each day. The data collected on site is summarised in Table 17.

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Table 17 - Planned versus actual data for the refurbishment of kitchens

Refurbishment of kitchens Cycle times (minutes)

Contractor A

Day Planning parameters

Actual data

Item Item of work K1

Occupied K2

Void K3

Occupied 1 Rip Out & Strip Out

1 120 100 85 120

2 Plumbing 120 100 90 120

3 Electrics 2 420 360 270 285

4 Plastering 3 420 360 225 405

5 Fit kitchen 4 360 330 240 310

6 Tile kitchen 5 240 180 225 210

7 Screed floor

(dry time) 6 60

(120) N/A N/A 30

(120)

8 Lay floor 7 120 60 60 90

9 Decoration 1st phase

(dry time) 8 240

(240)

210 (240)

150 (240)

210 (240)

10 Decoration 2nd phase 9 480 300 300 270

11 Handover (snagging &

cleaning) 10 480 160 160 160

The site manager is responsible for devising a plan for each refurbishment scheme set in the master plan produced by the project manager. This plan contains the list of properties, addresses, items of works, and dates. Figure 17 illustrates this plan.

Figure 17 – A production plan at the site office

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As shown in Figure 17, the table serves as a production plan for the entire refurbishment scheme and it is also used as progress sheet. The site manager uses colours to indicate which tasks have already been done. Based on this plan, the site manager develops a production plan for the week. In this regard, he said that there is no negotiation with subcontractors, i.e. he tells the subcontractor what he wants and if the subcontractor is not able to do the job, he gets somebody else. In addition, there are no monetary incentives in place to foster productivity. The weekly plan is displayed on the wall at the site office (Figure 18) and it is also communicated to foremen and subcontractors through a formal document (Figure 19).

Figure 18 - Weekly plan displayed on the wall at the site office

Figure 19 - Weekly plan sent to foreman and subcontractors

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The site manager circulates the weekly plan to subcontractors every Monday morning. Also, design drawings (e.g. electrical, plumbing, kitchens) are provided for the tasks scheduled for the week. In order to ensure the accomplishment of the weekly plan the site manager and the TLO visit the properties on a daily basis. According to the site manager, usually 100% of the planned tasks are completed at the end of the week. He said this is because he monitors the work progress daily in order to be able to get the project back on track

straight in the day after if necessary. Also, the TLO and the foreman are also constantly visiting the houses to check progress of works.

The foreman works closely with the operatives on site to make sure the works are being done up to the standard set by the housing association and to ensure the accomplishment of tasks assigned in the weekly plan. The site manager assists the foreman by providing whatever information he needs to keep the crews working continuously. He is also

responsible for managing health and safety, workforce, programme, and quality issues. The TLO is responsible for dealing with any sort of issue from the tenant’s side and to make sure communication has been done appropriately, namely, tenants are fully aware of what is going on in their houses.