Stanhope has tried to drive down construction time on previous projects, with limited success. "We've pushed as hard as we can, but the same mistakes keep on happening," says Peter Rogers, the developer's ebullient director. If MidCity Place was to be completed quickly and efficiently, Stanhope had to try something new.
The answer was to pilot a new computer simulation tool called DALI (for Design And Logistics Integration), that would allow the building's construction process to be modelled in 3D. The simulation will enable the project team to plan the most efficient way to construct. Rogers explains: "The program will prevent mistakes by ensuring the correct interface between different construction elements." However, construction sequencing is not the only discipline in which Rogers wanted to improve efficiency: the supply of materials to the site and their distribution around the building are also being computerised. And, to ensure that the new systems are fully challenged, Butler has set the construction team a target of 57 weeks to complete the building's shell and core, taking a full 11 weeks off the original programme.
The man responsible for completing the project on time and to budget is Paul Sims, project director of construction manager Bovis Lend Lease. "The 3D modelling is the most sexy thing we're doing here," says Sims. "It helps us to plan logically by allowing the team to construct the building on the computer before we get to site." Sims says that the system has helped communication and understanding and allowed the risk of any changes to the construction sequence to be modelled to assess their impact.
Modelling a construction project
The program was developed by Barry Ramsay, managing director of software house Architectural 3D. It takes a standard 3D drafting package and adds a construction-programming tool. As MidCity Place is the first live project for DALI, it is being as closely monitored by Architectural 3D as it is by Stanhope.
Creating the virtual building model involved collating detailed information provided by all the specialist contractors. Each had to produce a schedule for their individual package of work, listing every component and the date of its installation.
These component schedules, or build-plans as Ramsay prefers to call them, had to be produced months before work was due to start on site to enable the model to be created. For Sims, this exercise alone brought huge benefits: "This got the contractors thinking about project programming and manning levels in depth at a very early stage in the project," he says.
Once the model was complete, Bovis Lend Lease used 3D representation of the construction process to brief contractors before they arrived on site.
Using the 3D model brought other benefits to the construction manager. It highlighted obvious programming errors: for example, where a steel beam had been allocated an installation date earlier than the two columns that would support it, the beam would appear floating in space. It flagged up access problems to some areas, which resulted in the staircase being constructed earlier in the programme.
The model also illustrated potentially dangerous scheduling decisions. Ramsay uses the example of the huge curved overhang that crowns the building's main facade, which he affectionately refers to as the eyebrow. "When this facade was first modelled, it soon became apparent that construction of the overhang had been scheduled at the same time as the work to install the facade beneath it," he explains.
Now, nine months into construction, the programming tool is already beginning to prove its worth. Every morning, Bovis Lend Lease issues each contractor with a 3D drawing of its allocated work for the day, based on the information provided in the build-plan.
At the end of the day, contractors are responsible for recording their progress against this schedule to allow the model to be updated. Any areas where work is running behind schedule are highlighted. For the project manager, this information is invaluable. The consequences of any missed deadlines can be viewed by looking forward in the construction programme to see their effect on other trades.
The model also offers specialist contractors the benefit of viewing areas in which they are scheduled to work well in advance. The onus is on them to discuss with the project manager any potential problems caused, for example, by other contractors running behind programme. "On the micro level, the trade contractors look at their own work, while on a macro level they can look at potential conflicts of access or safety," explains Butler. Sims agrees: "It helps contractors take responsibility," he says.
The program also shows the history of the building's construction, and so also helps to eliminate claims. Butler calls it an "indelible record", although he is quick to point out that this is not the primary reason for Stanhope's use of the program.
Learning from the car industry
With details of every component already held on the project management computer, Stanhope seized the opportunity to improve the efficiency of materials handling at MidCity Place.
To do this, Rogers took Sir John Egan at his word and looked to the car industry. He invited Unipart and FX Coughlin, already working together to distribute and supply materials to the Jaguar S-type production line, to manage the supply and movement of materials to and around the site.
Stanhope had already been in contact with the two firms before MidCity Place. More than a year earlier, Rogers had invited them to produce a report on possible improvements in the management of materials on construction sites.
Neither company had worked in the sector before, so to gain experience of a site, they visited Stanhope's Christchurch Court scheme at Paternoster Square. "We bombarded everybody there with questions," says Unipart's Huw Jones. "Our report concluded that construction could learn a lot from the car industry." In particular, Jones was amazed that people started work on site immediately, without producing a detailed plan of work. "In the car industry you can spend up to three years planning before the production line starts to roll," he explains.
Pre-planning was one of the main difficulties Jones foresaw in the management of materials supply. The other problem was that construction packages were not defined in enough detail. "If you don't know exactly what work is planned for a particular day, you cannot pull the right materials from storage for that job," he says.
At MidCity Place, each package had already been defined as a series of daily tasks to allow the project-programming model to be developed. It was a synergy that Rogers was keen to exploit. Stanhope encouraged Unipart and Coughlin to develop software specifically for managing materials-handling in the construction industry. The result is ConstructionPro and, as with Architectural 3D, MidCity Place is the first application.
ConstructionPro works by scheduling the site's material requirements on a day-to-day basis. By linking these requirements to Architectural 3D's construction planning software, the team knew exactly where in the building the material would be required.
Before work started on site, Unipart visited every supplier to explain exactly how the system would work. "We needed to know the lead time for ordering materials and, once the materials were delivered to site, how best to handle them," explains Jones. The handling information was important; rather than the trade contractors stopping work to transport the materials to a storage area, Unipart proposed using a dedicated logistics team to move materials around the site.
"Industry productivity is about 30 to 50%," says Stanhope's Rogers. "By using a logistics contractor to feed materials to skilled workers, we are hoping to see a great improvement." Stanhope plans to run productivity tests next month to see how well the system is performing.
On site, the benefit of the just-in-time delivery system is immediately obvious. There are no piles of materials lying around waiting to be used, and no areas cordoned off for storage. "We only pull from storage all the materials needed the next day for a particular job," says Jones.
"It means that the site is safer and more efficient," adds Sims. With less material lying around, there is much less chance of it becoming damaged. "We have been wasting £1-2/m2 on damaged materials," says Rogers.
The success of many of the innovations used at MidCity Place will not be apparent until construction is complete. Sims, however, is already sold on the 3D management program: "We'll be running this on all Bovis' projects in the future," he says.
Stanhope will be benchmarking this project against other schemes, and Butler is hopeful that it will prove valuable. He says: "This is only a pilot scheme but it should allow us to take the fat out of construction."
Credits
client Matsushia Investment Development development consultant Stanhope construction manager Bovis Lend Lease architect Kohn Pedersen Fox structural engineer Waterman Partnership M&E engineer Roger Preston & Partners Quantity Surveyor Gardiner & Theobald
