As one way to cope with the challenging economy, many owners/facility managers are doing tenant improvements (TI) and facility upgrades. Contractors, who normally do not perform TI, are now competing in the TI market. Lean construction has proven itself valuable in large projects and also works in small projects, but in different ways.
TI differs from major projects not just in scope and size, but in the planning horizon, change orders, work structure and closeouts. The factors enter into how Lean is best applied in TI. Probably the biggest factor in these type of jobs is the speed of the work, planning must be done in shorter periods and closer to the start date. The work itself must be completed often in days, not weeks or months, and closing out the projects is also on a short fuse.
What remains a constant is that customers still want value. Value is the usefulness of the job performed, compared to the costs. These costs include the dollars paid, the time the customer waits to obtain and use the facility, as well as the pain (hassle or inconvenience).
Price is always a customer concern, especially in today's market. Price is most often the deciding factor on who gets the job. The contractor that can provide the lowest price while being able to maintain a reasonable profit margin will be the winner in the long run. Contractors, who apply Lean, will find more opportunities to eliminate waste in their delivery of work and will reduce the risk of losing business and profits.
Lean works to reduce wastes in ways typically ignored by contractors. There are seven basic types of waste identified through Lean, which are:
• Defects in purchased, fabricated and installed work.
• Over-production of goods is waste when we order more material or parts just in case we might need it. This happens when we fabricate material too early and or stockpiling it either in a warehouse or at the jobsite.
• Inventory is waste, including unfabricated material, work in process and finished products. If the material is not yet installed and being used by the customer, it is waste. Spare parts, unused tools, consumables, and employee stashes and personal stockpiles are waste. It is not possible to work with zero inventory at a job, so some inventory is necessary. "How much is enough?" is the ongoing challenge.
• Transportation of material in the shop, yard and on the jobsite is waste. It maybe necessary, but is not value added.
• Waiting is also a waste. When something or someone is waiting, it does not add value. Because of the urgency usually associated with TI work, a crew waiting or room to be remodeled is an especially noticeable waste.
• Over-processing is waste. Any work steps that do not add value are excess and waste.
• Movement of people happens when workers go looking for tools, material or information. This waste happens everywhere in construction.
Lean tools reduce waste
Use the 5Ss to organize the workplace. Tools and equipment can be organized and managed to avoid or minimize the treasure hunting. The 5Ss allow crews to focus their efforts on value added work and do it quickly.
• Make all consumables available. Avoid excessive amounts (inventory) by using Kanban methods, a communication tool used in Lean production systems. Kanban is a Japanese term meaning “a signboard.” The signal tells workers to pull parts or refill material to a certain quantity used in the fabrication process. The signal can be a minimum fill line, an empty first bin of a two bin system or some other way to show it is time to refill before one runs out. A two bin and min–max with replenish signals methods are the most frequently used kanbans.
• Fabricate as needed. Don’t do it too early and/or deliver it to the work area too soon. Ideally, the material is delivered and installed with little or no wait time in the shop or at the site. To accomplish this requires effective planning and communications. Reducing the batch size of material drawings and order quantities will help. One contractor reported fabrication material during the day and their crews installed it each night.
• Use Spaghetti charts in advance of actually doing the work to minimize the movement of people and material. Draw the path the work should go and observe the actual path. Adjust the actual path to minimize travel time and people movement.
• Make it visible. In Lean applications we want to make work visible, so one can quickly see if work is being done as planned or something is not "normal" in the work process. Use a board at the jobsite to show the work tasks planned by trade for each day and week. Show priorities using color codes. Mark completed work daily. Hold daily huddles to keep crews working on priority work.
Use the Last Planner System
While the Last Planner System, a registered trademark of the Lean Construction Institute, in its full application may not fit TI work, the basic parts do still apply. These are:
• Doing a simple pull planning session with all trades involved can be very valuable to TI work. The collaboration and consensus on the work sequencing and task handoffs generated during a pull planning session is critical to effective work completion.
• Use a one or two week look-ahead. The work to be done should be broken down into tasks and each task "made ready" by having the right material ordered, the right equipment in place, all changes and plans approved, etc.
• Each week should be planned and sequenced correctly. At the end of each week the work should be evaluated, the tasks completed noted and any barriers to completing all planned tasks identified.
• Planning system measured. The average work crew completes about 54% of the tasks they had planned to do each week. This measure - PPC (PPC = percent of planned work completed) is a useful indicator of the effectiveness of the planning process.
• Constraints Removed. PPC will only consistently improve as the barriers to completing planned work are minimized or removed. Hold daily/weekly discussion on these constraints and how to remove them.
There is much TI work being bid in today’s economy. Success is not just getting the job, but making a profit on it. Lean has many tools to help accomplish this.
Dennis Sowards is an industry consultant and guest writer for Contractor magazine. His company is Quality Support Services Inc. He can be reached at [email protected] or at (480) 835-1185.