4 Development of the LCM model: Case Study 1
4.6 Step 4: Demonstration of version 1
4.6.1 Description and application of version 1 during instantiation 1A
The original version of the LCM model, consisted of 9 main visual elements; the Overall Process Map (no. 1, Figure 4.7), construction cards per company (no. 2, Figure 4.7), the daily planning board (no. 3, Figure 4.7), an apartment clock (no. 4, Figure 4.7), a construction checklist (no. 5, Figure 4.7), visual KPI’s (no. 6, Figure 4.7), a logistics board (no. 7, Figure 4.7), an information board (no. 8, Figure 4.7) and an action plan (no. 9, Figure 4.7). The Overall Process Analysis had been carried out as a first step, before the development of the remaining visual tools (Section 4.4.1) and was used as basis for splitting down work and structuring the planning board. All other elements are applied together onsite and require input from construction management, company representatives and the participants at worker level. In this way they fulfil the objective described in Section 4.4.3, which is to ensure involvement of construction workers in the improvement process. The remaining visual elements of version 1 of the LCM model are as follows:
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4.6.1.1 The construction card – “levelling the workload”
The objective of the construction card is to facilitate the process of splitting work down into daily packages so that the work could be evenly dispersed across the weeks visible on the planning board (Section 4.4.2). The construction card (no. 2, Figure 4.7) represented a unit of work, e.g. the installation of floor heating in apartment 1. An example of a construction card used during instantiation 1A of the LCM model can be seen in Figure 4.8. The cards were prepared by the foreman, together with the researcher and the subcontractors weekly, so that a detailed plan of work was available two weeks in advance. The cards also display the estimated worker capacity needed, the required building materials, the date, area and other relevant details. This information helped to control the amount of material building up on the site, as only material that was needed for the time period specified on the planning board was ordered.
Each day, the card for that day was collected by the worker in the morning from the planning board and taken to the area of work. At the area of work the card was placed on the “apartment clock” to indicate work in progress. When the construction worker finished his work, he turned the card around to indicate to the foreman that the work is completed. The foreman then checked the quality of the work and if everything is ok, the card was then replaced on the daily construction board, “green” side up, by the foreman. This process is illustrated in Figure 4.12.
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Figure 4.8: Construction card front (on the left) and turned around to face the green side (right)
4.6.1.2 The daily planning board – “visual pull system”
The objective of the daily planning board is to implement a visual pull system onsite, to facilitate the flow of leveled work (Section 4.4.2). The daily planning board (no. 3, Figure 4.7) is the “heart” of the LCM model. During the LCM instantiation on the construction site, the daily and weekly planned work packages were displayed on cards on this board, which was placed in a central area on the building site (Figure 4.9). These work packages were carefully defined and planned by the researcher, together with the foreman and subcontractors involved. They were based on work derived from the previously defined standard process, aiming to introduce flow in the work onsite.
In addition to implementing flow in the construction process, another effect of visualising these work packages was that once the cards were placed on the board it was clear to see in
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what areas of the site no work was being carried out (see nr. 1 and 2 on Figure 4.9). This enabled the foreman and contractors to “see” what work was carried out, where and to identify vacant areas where no work was being carried out. In addition, if a problem was perceived in the process, a problem card was placed in front of the construction card on the board. This was a signal that the work could not be carried out until the problem (described on the problem card) was resolved. It highlighted an opportunity to reduce the overall lead-time, since worker gangs could be dispersed in a more effective way so that work flowed through the building and subcontractors did not hindering each other’s progress. The visualisation of the daily activities in this way created transparency in the daily operations and a better understanding of the process in execution which could not be achieved by just using the master plan. The standard process as illustrated in Figure 4.6 was used as a source for the contents of the construction cards.
During instantiation 1A, the “standard process” included all process steps necessary to construct one apartment unit. Each apartment was visible on the planning board and just by taking one look (Figure 4.9) the status of work onsite at that particular time could be established. For example, it was clear what work was finished in what area (cards turned around to green side), which work had yet to be completed (coloured cards still positioned on board), which work was currently in operation (red spots indicating card has already been taken from the board) and where work could not be carried out for certain reasons like plaster drying (stop signs). Once the completed green cards were checked (nr. 5 and 6, Figure 4.7), data was gathered in terms of quality and On-Time-Performance (on this particular site, these were the factors considered most important by the foreman). The process of gathering, analysing and visualising performance measurement is described in Section 4.4.5-4.4.6. At the end of the working week the goal was to have a full green board indicating all work completed at an acceptable level of quality (see number 4 in Figure 4.10). The planning board was the central meeting point for the start of work each day and was the last stop for workers on leaving the site.
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Figure 4.9: The planning board
Figure 4.10: The planning board process
Displays current week and following week
These are stop sign cards indicating that work cannot be carried out in this area at this time (drying). Optimal flow of work in apartment Each green card is a successfully completed package of work Each row
displays one apartment
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Status at the beginning of the week
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Status at the beginning of the week
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The red points are markers for cards that are in process and currently hanging at the place of work
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4.6.1.3 The apartment clock – “facilitate regular quality checks”
The objective of the apartment clock is to visualise work in process at the area of work and to provide a mechanism for the regular quality check of that work (Section 4.4.5). The apartment clock (Figure 4.11 and Figure 4.13) was the only element of the LCM model that was visualised away from the planning board and instead displayed at the actual area of work (at the entrance to each apartment during instantiation 1A). The apartment clock visualised all steps to be taken to complete one apartment and what the current status of completion was. The process steps were written in text on the activity column and the status of the work in progress was indicated by the hand of the clock pointing to the activity that was currently in progress (Figure 4.11). The construction card was hung on the apartment clock by the construction worker to indicate which work was being carried out at the particular time. When the construction worker was finished his work, the card was turned around to the green side to indicate to the foreman that work was complete and should be checked. After reviewing the work, the foreman decided whether it met the correct quality standard or not. If not, further improvement actions were defined in discussion with the construction worker. If further measures were necessary, the foreman then turned the card back around (Figure 4.13), making a note of what had to be completed and updating the KPI’s. If the foreman was satisfied with the quality, he returned the card to the planning board, facing it the green side up. This process is illustrated in Figure 4.12.
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Figure 4.11: The apartment clock
Construction card displaying current work process Status of work in one apartment Optimal process
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Figure 4.13: The apartment clock showing foreman requests
4.6.1.4 Construction checklist – “facilitate quality checks”
The objective of the construction checklist (Figure 4.14) was to facilitate the foreman when carrying out the daily quality check of work (Section 4.4.5). This aid was used for three main reasons:
It was a paper copy of the “work packages” (construction cards) that had been agreed on, in the event of cards going missing from the daily construction board.
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It replaced the original protocol sent out by the foreman to the building contractors, so that everyone was aware of agreed work in the pipeline.
It was used by the foreman as his guide to know where to expect completed work to check, on any given day.
Figure 4.14: Checklist used by foreman
4.6.1.5 Visualised Performance Measurement – “transparency of performance”
The objective of the visualised performance measurement is to make performance of individual subcontractors and the quality of their work transparent (Section 4.4.6). Each afternoon, the daily construction cards were reviewed by the foreman (nr. 1 and 2 in Figure 4.16). Data for metrics such as quality and On-Time-Performance were gathered by the foreman, displayed and discussed at the weekly site meeting. The On-Time-Performance (OTP) metric is similar to the Percentage Plan Complete (PPC) in the Last Planner System (Ballard, 2000). Both metrics measure the extent to which commitments are realised and this measurement is expressed as a percentage. PPC is the number of planned activities completed divided by the number of planned activities expressed as a percentage. OTP is number of
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cards completed by the subcontractors (which are a pre-defined daily work package of activities for a specific area) divided by the total number of planned cards expressed as a percentage.
The quality and OTP metrics were calculated in a very simple way: the work on completed cards (green) was checked on a daily basis. If a company had planned to complete 6 cards and only completed 3, their On-Time-Performance was 50% (an example of the On-Time- Performance metric can be seen in Figure 4.15 (b)). From the number of completed green cards, a metric was calculated to reflect the level of quality (see Figure 4.15 (a)). The goal for quality was always 0 (Zero defects) so if 6 completed cards had just 1 quality mistake the metric would be 1/6 = 0,16. If there were 2 defects the metric was 0,33 and so on. The more defects, the further away from 0 and the lower the quality KPI would be. Corrective actions were noted and displayed on the action plan to be completed as soon as possible (number 4 in Figure 4.16). Progress of performance was monitored and displayed on the site information board (number 3, Figure 4.16). Positive results generated a positive atmosphere on the job while negative results encouraged participating companies to do better. It was observed by the researcher that the visualisation of the performance metrics helped to generate a positive element of competitiveness between the participating companies: the subcontractors generally did not want their company to represent a low performance level.
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Figure 4.15 (b): Measuring On-Time-Performance as a KPI
Figure 4.16: Process for gathering KPI’s
Project start Current status
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Kennzahlen Kennzahlen Update daily plan Action planPositive development of KPI‘s
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Kennzahlen Kennzahlen Update daily plan Action plan135
4.6.1.6 The logistics board – “site management”
A further element of the LCM model was the logistics board (see Figure 4.17). The objective of the logistics board was to improve material organisation and storage onsite (Section 4.4.4). From the planning board, it was possible to more accurately estimate what material would be needed in the coming weeks. The logistics board visualised and controlled the designated areas for material storage. When suppliers arrived with material, they checked the board to see where to store the material they were delivering. This resulted in less walking, searching and less co-ordination of material needed onsite. This process is illustrated in Figure 4.18.
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Figure 4.18: The logistics board process
4.6.1.6.1 The information board - “promote continuous improvement”
The objective of the information board (Figure 4.19) is to display all information relevant to the construction site: progress on KPI’s, examples of quality issues, positive feedback. It enabled open communication on the building site and encouraged continuous improvement (Section 4.4.3 and 4.4.7). All workers at all levels from each company viewed this board to check general construction progress and news.
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Results: Less walking Less searching Less co-ordination No double transport Transparency for suppliers and construction workers Planning board Storage area allocationMaterial delivered to defined storage areas
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Transport to work area1.
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Results: Less walking Less searching Less co-ordination No double transport Transparency for suppliers and construction workers Planning board Storage area allocationMaterial delivered to defined storage areas
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Transport to work area137
Figure 4.19: Information board at construction site
4.6.1.7 The action plan – “facilitating continuous improvement”
The objective of the action plan was to capture problems and their solutions identified in the construction process. Ideas from construction worker level were discussed (Section 4.4.3) and solutions defined, documented and visualised, thus facilitating continuous improvement onsite (Section 4.4.7).
Since completed work is checked on the evening it is completed, any minor issues that arose could have be taken care of immediately (since in most cases the construction worker was still present). Alternatively, problems were noted on the action plan (or the apartment clock) to be addressed the following day (Figure 4.20). The action plan was also displayed beside the planning board in the central communication area (LCM area). Since these issues were visualised, a greater awareness of the problems was created and also a greater interest in resolving them, as they remained on the action plan until they were implemented.
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Date Responsible Status Target date Date
completed
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Action plan:
Identify and prevent problems on the construction site
Problem Action D C E A P D C E A P D C E A P Figure 4.20: The action plan