2020Case5Sisk

Contents Lean Construction Ireland Annual Book of Cases 2020 21 Case 5 We focused on the following seven key Lean Concepts: i. Training and creating awareness of Lean principles. ii. Collaboration between all parties (designer, main contractor, and concrete frame contractor). iii. Understanding the customer requirements. iv. Map the value stream and focus on the detail to improve flow. v. Maximise efficiency of plant, equipment, labour. vi. Productivity of labour, measure and monitor output. vii. Direct observation studies to aid productivity. Training and awareness of Lean principles The project team were supported from pre-commencement stage by Sisk in-house Lean specialists and through external training and mentoring delivered as part of our Lean Transform programme. All of the Sisk project team were trained as Lean Yellow Belts, with workshops between Sisk, designers, and contractors helping to secure support for the Lean execution approach. Collaboration between all parties We selected our concrete frame partner not only on the basis of cost, but on their previous experience. They had worked with us previously, understood our open project approach, and were committed to investing and contributing to a collaborative approach. The design team were also keen to engage. Understanding the customer requirements For the purposes of the concrete frame, we considered the design team and our concrete frame contractor as our customers. The structural designers needed a building that would be strong enough to fulfil its structural functions, as well as being structurally sound in all temporary conditions (mid-construction). The architectural designers needed structural detailing that would allow them to support the external facade for example. The mechanical-electrical designers needed to allow for openings in the structure for the passage of services. Our frame contractor needed a design that facilitated efficient construction, needed space onsite to lay down shutters and needed to limit any unnecessary use of materials, plant, or labour. Sisk itself was the customer of both the design team and the frame contractor, and we needed a design that maximised our efficiency and a rapid construction within a budget. Map the value stream and focus on the detail to improve flow The building had been designed to suit the final architectural and structural requirements, for example, four stair towers were designed to be constructed floor-by-floor in the same timeframe as the columns and slabs adjacent, and the elevated floor-slabs included a downstand beam on the perimeter of each floor. The collaborative process concluded with a revised design, a standardised layout to suit the formwork systems of our frame contractor, and a revised stair tower design that facilitated early construction of the stairs to full height. This was a win-win solution – not only did the frame contractor now have space to lay down their bulky wall shutters, but they could also significantly shorten the overall hire period for these wall shutters and remove cranes from site at an earlier date. The designers also had more time to design the main floorplates by releasing the stair cores early. Working together, we redesigned the internal leaf of the facade from blockwork to a lightweight steel frame system. This resulted in the removal of a concrete downstand to the perimeter of the reinforced concrete frame which provided a flat slab and soffit for the formwork system. We standardised the wall and column sizing to ensure that the formwork system was interchangeable between pours and did not have to be split and rebuilt following each concrete pour. Maximise efficiency of plant, equipment, labour The construction of an in-situ concrete frame can be broken down into a four-step process: install formwork; install reinforcing steel; pour concrete; and strike shutters. The plant and material resources are different for each step, and each step typically involves separate personnel. Planning the work to ensure continuity of efficient work fronts for everyone is difficult and depends on developing a cycle time and rhythm to the works. Lean Initiative Undertaken – Lean Thinking, Tools, Techniques Figure 2. Downstand Decking System & Flat Slab Decking System