2018Case5BanagherPrecastConcrete

27 L EAN C ONSTRUCTION I RELAND A NNUAL B OOK OF C ASES 2018 BIM, but as part of BPC’s Lean strategy it was decided to use BIM anyway for internal use to map the entire project to remove waste, to implement right-first-time (RFT), and to deliver just-in-time (JIT) rather than holding stock. The detailed modelling of the structure provided BPC with the requisite information to avoid errors, to map a concise manufacturing schedule, and to ensure delivery in full as products were required on site. The primary issue with using BIM is that the initial set-up of a BIM model is extremely time consuming and requires absolute precision detailing. It also requires commitment from the entire team from the outset and throughout the entire lifetime of the project. When BIM is not a client requirement, the leap to implementing it internally on a project is a significant break from the traditional way of operating. Figure 3. Timber Mould with Rebar Cage In-Situ Before Concrete Pour. Mould Efficiencies Precast concrete products are manufactured off-site and include reinforced items such as bridge beams, columns, terrace units, walls, and parapets used to create everything from buildings to bridges and stadia. The process of manufacturing precast products includes steel and timber moulds – a rebar cage is dropped into a specially designed mould and concrete is then poured into the unit and left to set. New steel moulds typically cost upwards of € 10k each. Timber moulds can only be used on average for 20 pours and are very t ime consuming to make. Once the dimensions of a piece changes, so too must the moulds. BPC provided a total 13,000 tonnes of precast concrete, consisting of over 3,000 separate pieces of precast, to Páirc Uí Chaoimh, of which there were 800 different sizes, necessitating the requirement for over 16 moulds. On waste management walks prior to the project starting it was identified that some existing moulds could be used instead of commissioning new ones. It was also identified that if BPC moved away from standard practice and traditional methods – which were both costly and time consuming – and invested in new technology, it would reduce the number of moulds required from 16 to 4 and improve overall productivity. BPC researched best practice options and invested in adjustable steel moulds with magnetic features which reduced the number of steel and wooden moulds required, saving the company over 3% of the project value on new moulds and almost the same again in workable hours. Reducing the number of moulds also meant that all production could be carried out in the one area closer to the batching plant and stock holding area – all of which provided further cost savings over the lifetime of the project. The moulds were also designed and/or modified to facilitate rapid de-moulding using the Lean practice of SMED (quick changeovers) modelled on techniques applied on Formula 1 Pit Stops. Figure 4. New Adjustable Steel Moulds. Process Mapping: BIM The Lean team focused on the traditional 2D method of planning and process-mapped how a typical project runs from start to finish, highlighting inefficiencies and areas where errors were most likely to occur. The process mapping demonstrated from the outset that using the traditional 2D method was bound to create complexities and errors in the project. Hence the first decision taken was to move away from 2D and implement BIM instead. Process Mapping: Product Moulds The process mapping also highlighted the adverse cost and time implications of using timber moulds and purchasing new job-specific project moulds, and this led to these improvements and capital expenditure in adjustable magnetic moulds. The team also process-mapped an individual piece of precast and identified time inefficiencies throughout the manufacturing process. As a result, the team decided to condense the project to one manufacturing area within the production plant, and placed it close to the raw materials which were required continuously to ensure that time was saved. Plan Do Check Act: Samples During the process mapping the importance of creating master samples for Client approval was identified to reduce errors and ensure that both BPC and the Client were aligned. This resulted in master samples being created, stored, and used as a benchmark for all subsequent products in the project. Plan Do Check Act: Trial Fittings The process mapping also highlighted the importance of carrying out trial fittings in the manufacturing facility prior to mass production to ensure that all products would fit correctly when being erected on site. Trial fits are expensive, time consuming, and complicated as internally BPC doesn’t have instal lation experience; however, the benefits of planning, manufacturing, checking, and carrying out the trial fits meant that the Client could verify the products, that potential issues were highlighted and then avoided in mass production, ultimately resulting in zero errors and ensuring RFT delivery on site. 5S 5S workplace organisation has been deployed across the site resulting in greatly enhanced safety through reduction of workplace risk, a better work environment for frontline staff, greater customer perception, greatly reduced employee search time for production suppl ies, and significant savings in employee walks for components and supplies not at point of use. Over 3,000 individual 5S improvements have been implemented across the site. Additionally, over 1,000 implemented ideas by frontline staff have been realised via the company’s local visual idea