In construction we are familiar with the graphic above when it comes to controlling safety hazards. I suggest that it also applies to the other challenges that we have on our sites. Do our sites go over budget? do they go over schedule?
What are the equivalents that we can compare to the systems that we work in?
In the extremes we would have Elimination, where we redesign the system. We take the time to understand the value flow within the system and eliminate the wastes. We manage by means and ensure that people are following the system as designed, the system is modified of the outcomes are not what we want.
With Substitution, we look at the process that we are going to build and would use buffers to control against the variation in our system. The 3 main buffers that we use in construction are capacity, material and schedule buffers. This is where we balance an excess of these 3 items to make sure that we won’t be affected by the random events on our projects. For example, I could have extra door frames on site because I don’t know how fast they are going to be installed. Or, I could have an extra power trowel available to finish the concrete in case one of the ones that I have breaks down.
On the other end of the spectrum, where you find PPE, this would be the equivalent of motivational quality posters and chats from leadership where they come in to tell you to just do better and work harder. Like PPE they can be some benefit and they are easy to implement, but the effect is limited and the issues are still there.
For Administrative Controls, I see this as picking one thing that we are really going to focus on to ensure gets done right and all other things are basically left to their own devices. For example, a frequent one is elevators. We will be ready for elevator install no matter what, but other things are done out of sequence like having the tile in the lobby done so the elevator can be set, before the overheads in the ceiling are complete.
Our Make Ready planning and constraint removal is really a form of Engineering Control because we are isolating out the tasks that are not ready to be scheduled into work, and those tasks that are getting close to be scheduled we are guarding them and trying to make sure that we will have what we need so that we can schedule them when the time comes.
What do you think are some equivalents to the safety hazards and the process hazards that we have on our projects?
I recently completed reading the book The Lean Builder. The book is a very light and informative book. It uses a narrative style similar to Everything I Know About Lean I Learned in First Grade, which makes it very approachable to anyone, including those out in the field on the tools.
The book should be read in it’s entirety before implementing the principles outlined in it. I don’t agree with the order of implementation that they used in the book, but it might work for some people. I do agree that a phased roll out of the Last Planner System is a good approach as to not overwhelm people with too many new things to have to do at once.
It has the following chapters in it:
Chapter 1 – Daily Huddles Chapter 2 – Visual Communication Chapter 3 – 8 Wastes Chapter 4 – Managing Constraints Chapter 5 – Pull Planning Chapter 6 – The Last Planner System
In Chapter 1 they did a great job at capturing the essence of a trade meeting and I have been in many just like that. They did highlight the importance of committing to each other, but not very directly. One of the Five Big Ideas is that a project is a network of commitments. As it was early in the book and they do not discuss the Last Planner System until the last chapter they didn’t discuss how their daily work connected to the bigger picture of if fit within the milestone and phase that they were working in. It is really easy to get lost in the weeds when planning the work for the week to not consider how this ties back into the bigger plan. This is why I recommend that there are two people on the General Contractor side working on the plan. One to coordinate the plan and the other to be checking to see if that fits in the bigger picture.
Visual Communication is a foundational piece to Lean. It allows everyone to see where everyone is at. As well, it keeps people aligned to the same goals. When we are showing metrics we should ask ourselves is the best way to show this metric? Are we getting the results we thought out of this metric? Does it still matter? A metric might be good initially but when we move to a different phase it may have less impact. So we use our metrics and any counter measure to solve a challenge and help us improve. If it is no longer useful, stop doing it. We only want to do value adding work.
Another visual communication tool that I use is the personal kanban board. It allows me to see where I am with the various tasks that I have. The challenge is to stay strict to a WIP limit, as we all know that multi-tasking is inefficient and will make all the tasks take longer than if we just stayed focused on the task at hand.
There are many ways and acronyms to describe the 8 wastes. They used the DOWNTIME example and I prefer the TIM WOODS. I actually came across a great graphic the other day that put them in order with the worst wastes first. Which was an eye opener to me as I had never considered which waste was worse.
Ohno’s 7 Wastes
Defects
Waiting
Over-processing
Overproduction
Travel/Transport
Inventory
Motion
When you think about it, the first 3 are fairly intuitive that they are worse than the following 4. Defects are building the wrong thing or the thing that doesn’t meet the parameters. Labor is typically expensive in the Western world so a waiting is highly expensive to the process and Over-processing is creating something to a higher tolerance than is required by the subsequent step in the process and in the specifications. Though we also know many engineers that specify tolerances too high for what is required.
Constraint Management is the heart of the Last Planner System in my opinion and they had some great insights there. It is important to have it visual and that each team member owns their own constraints.
Pull planning is where everyone likes to put their time in. It gets the most training and there are a bunch of software solutions that are hitting the market that enable it to happen virtually. The handoffs are the key part of the conversation here, and that it is important to give everyone a voice. This usually takes some practice to facilitate and I usually recommend that there is a co-facilitator there to make sure that you stay connected to the Master and Phase plans. Some people recommend that you pre-populate the sticky notes before I hand, that is not usually how I operate as you are making assumptions on what people are going to request or pull from you to do.
Pull planning is just one tool as part of the Last Planner System (LPS) and is usually done in the Phase Planning portion of the system. It is called the Last Planner System because the Last Planner is the last person making the assignments to the workers and most intimately knows what is required to get the task done. It is a construction made tool that helps make the planning more reliable and predictable. If reliable and predictable scheduling is not your issue than use a different lean tool first. Just like Lean is not used in every automaker let alone every manufacturing company I doubt we will see industry wide adoption of this tool. When a company chooses to use the LPS system they are engaging in a new culture of doing work. It is not about command and control but about collaboratively working together to bring value all along the supply chain directly to the client.
As I mentioned above, it is a great introductory book to the principles of Lean in construction. I would recommend it to anyone, especially those in the field, our last planners and our superintendent. Just with any learning, it is a first step in your lean journey and can help you further develop your knowledge in this exciting corner of the construction industry.
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Recently I had the opportunity to do some roofing for my parents on their garage. It was good to get on the tools as it is not something that I get to do very frequently anymore. It reminded me of my youth working on the family farm and the numerous projects that I found myself involved in, back in those days I was always looking for an easier way to do the work. Fast forward all these years and I have a vocabulary to describe what I was seeing back then.
Being a Lean practitioner I have some ability to see non-value added work vs value added work. I am able to describe the wastes that I saw. I was also able to help myself by trying to structure my work in the most effective way possible. Now, I do say try as I was unfamiliar with the work. My knowledge on the subject comes from the building science that I have gleaned from working in the industry for a number of years, watching a few YouTube videos and reading the manufacturer’s packaging on the shingles themselves.
Work can be broken down into Value Added tasks, necessary but non-value added and obvious waste tasks. Value added tasks are those that give the client/customer what they want. It is the transformation of goods into the product that they are willing to pay for. Or in other words it achieves the form and function that they desire. In my case, my parents wanted to have a roof on their garage that matched the roof on their house that they had replaced last year. The function is that it protected both the structure, to maintain their property value, and to protect the contents that they hold within the garage. So any task that is not working directly to that goal is not of value to them. Non-value added tasks break down into two main categories, necessary and pure waste.
There were times that I would have to pause from installing shingles to plan out the next steps, or when I was doing cuts on the edges, I had to plan out the next few rows. This was mostly because I was just learning the trade of roofing and was figuring out what the next step was. At the start of the roof I was consciously competent of my lack of knowledge of the task ahead. It took a lot of effort to plan out each step. It would get a bit overwhelming if I thought to far ahead and all the tasks I needed to do to complete the roof. As I progressed through the work I became more competent in the tasks and I was able to focus on more things around me, like the pure waste that I was observing.
The pure wastes that I was observing are frequently known in Lean as Muda or the 7 wastes through the pneumonic TIMWOOD. They are Transportation, Inventory, Motion, Waiting, Over-processing, Over-Production and Defects. I tried to reduce many of these wastes but as it was a one off project for me and I was unskilled in the set-up I did not get them all in my first run.
Transportation waste has to do with unnecessary movement of material and equipment. I tried to reduce this waste in several ways. My mother and I went to the store in one trip to get the material required. Though the hardware store sent us home with the wrong nails so that required a second trip to get the correct ones, which was pure waste. When we loaded the shingles on the roof, we only took up half of the lot as I didn’t want to have to shuffle them around once I got up there and installed a portion of the roof. I made a rule to that whenever I went up the ladder I had to take something up, so I would take a bundle up to conserve trips. Now, there was some transportation on the roof as the bundles were near the peak and I would have to bring a bundle down to where I was working. I got better at figuring out where to stage a few shingles so that I could maximize the tool time when I was using the air-nailer.
Inventory was kept low on the roof as mentioned above as each time it is moved it is susceptible to damage. Once the package is opened there is a risk of pieces being picked up by the wind and causing damage or injury. Also, this took me a few days, so I wanted to minimize the risk of a bundle sliding down the roof as well. It is good that I didn’t bring up all of the bundles as we had three left over and I would have had to bring them down off of the roof. The take-off that was done was based on roofing contractor completing the work. They tend to have more cut-offs then I did. I saved the cut-offs and used them in the next place that they fit. By the time I was done I had barely a handful of garbage for the waste bin.
This leads into Motion waste, which involves any unnecessary movements to complete the task. As I mentioned I tried to keep a bundle nearby or stage shingles near where they were going to get installed. I tried to keep my hammer and shingle knife with me. But I had to measure and check and adjust several times as I wasn’t confident in my skills. Though I tried to keep my tools with me they were frequently not nearby and I would have to go and get them. Or I would run out of nails in the air-nailer. Now the air-nailer was a definitely a help to reduce motion, as four nails had to be put in each shingle and hand nailing those would have taken a long time and unneeded effort. My Dad, came up on the roof one evening and he was passing me the shingles and production was going really quick when I didn’t have to go and get more material or nails.
Waiting was not an issue on this project as I was doing all of the work and no process was held up waiting for the next process to start. There was no information that was required to complete the project. Even when my Mom went to get different nails, I had other tasks that needed to get done so production was not halted on the project. Another way to look at where I was waiting as mentioned above in the previous paragraph was when I was not attaching shingles to the roof the project was waiting for production to happen.
Over-processing is an easy one for me to do. This has to do with doing more work than is necessary to achieve the conditions of satisfaction from the client. Going above and beyond what is valued by the customer. This doesn’t mean not producing a quality product, it just means that I had to be aware of what the tolerances were. For example, the manufacturer’s instructions were to cut 6.5 inches off which was approximately 1/6 of the shingle. I could have gotten out a square and a measuring tape and cut each shingle to the exact length as described, but that wouldn’t produce and extra value. On the other end of the roof I was just going to trim off the excess and discard the rest. The trick is to know why we are doing certain tasks and to understand the tolerances required and to question them if they seem to high or too low. These should be communicated to the person on the tools so that they don’t have to make the judgement call. This should be also indicated by tolerances in specifications and production drawings. In this case the purpose was to offset the seams of the shingles so that the substrate was covered.
Over-production was like waiting and not really a concern as it was just me doing the work. Though it was windy so I didn’t put down the underlay membrane on the second side until I was ready to lay shingles on it as I didn’t want it getting torn off with the wind.
Defects is the last waste on the list. As I was not highly skilled in these tasks I made a few defects. I was aware of my conscious incompetence and started on the side that was not visible from the deck, so that I had space to learn. The shingles would come paired back to back and when I was starting I missed that I hadn’t separated them and nailed down a pair. There were a few slips of the knife that scored the shingle but some creative overlapping fixed that issue. As I was laying the shingles in a staircase fashion I did miss one of the lower steps once, which required me to pull out a few shingles and re-install new ones. I did like these shingles from Owens Corning as they had a fabric nailing strip on them which was a good visual on where to put the nail and it helped prevent it from going through the shingle as well. As the shingles look like shakes and its a dark color, I will admit that I did veer off course a little bit, but the shingles hid a lot of my high variation in the rows. It was not egregious but if you walk up on the roof you will see a little wave in the shingles.
The bonus waste that is frequently added is under-utilized talent. I can tell you that I was not under-utilized at this point for me signing up for the task. I gained in competence as I went and was glad for the experience. I think there is some value for people that spend their time in a managerial role to pick up the tools from time to time and get in the trenches with our craft partners as they help transform their raw materials into the products that our clients are desiring and paying for. It was also confirming to me that the Lean principles which I try and champion and share are apart of what I do and can also be seen by the guys on the tools if we help them see and trust them to make the work better and reduce the non-value added tasks from the work.
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These are turbulent times that we are in and variation is extremely high right now in April 2020. The concepts of buffers and how and when to use them is not a common discussion in Lean in Design and Construction. Sometimes they happen on the side or inadvertently. But now is the time that we need to be extremely conscious and deliberate in our discussions and use of buffers.
First off, what is a buffer? A buffer is a tool that we use to manage against uncertainty and fluctuations within our production systems. It is part of our risk identification and management strategy. The three main buffers that we can use are manpower, material or schedule (time).
In a normal construction project it is common to hear the superintendent say to a trade craft partner to “get more guys”. That is typically because he feel that production is not where he feels like it should be. But it could be because he sees upcoming work and wants to be prepared for this work. Or it could be because he feels more comfortable with an ant hive of available workers ready to “go to work”. Well this mentality leads to the waste of underutilized talent. And in our typical market of tight margins on projects this doesn’t happen all to often. Also, our trade craft partners do not typically have a corral of staff waiting back at the office waiting to be deployed. This is even more so now with the restrictions on staff if they are not feeling well to be not available. And fewer people are available for the demand at the projects. So we cannot rely alone on just getting manpower anymore.
Material can be an easy buffer and our contracts typically encourage us to use these unwisely. We are incentivized to bring lots of material to site as we are only paid on that material when it is landed on site. The only times where we are typically restricted from bringing material to site is when there is just a physical restriction to being able to place the material there. Having too much material on site can lead to waste. The material can get damaged or lost. The material is in the way and needs to be moved somewhere else which ties up manpower that could be focused on value added tasks. This is where the concepts of Just-in-Time delivery come into play. Ideally the material is unloaded and put directly into its final place. That is not always practical and appropriate for the risks that we have to analyze. Is the material readily available in small enough loads, then we could consider ordering smaller loads as demand calls for? But for rare material that has to cross international borders, or material that takes a long time to produce and the impact to the project would be great if we missed our deadline then we need to size the buffer appropriately and get that material there potentially sooner. We just have to be conscious of that decision. I was on a project recently and the freight elevator was inoperable for a month. When it did become available again the decision was made to get all the required material on the required floors as waiting for the elevator would impact the project immensely. Later the elevator was inoperable again for a week, but it didn’t affect the project.
The last buffer is time or a schedule buffer. There is a great discussion on how we implement these buffers on our projects. Due to the culture of deception, and “grinding” of our craft partners on schedule they like to include extra days in their time during the pull plans. Once a culture of trust has developed on a project that we will respectfully hold each other accountable and we use missed promised dates as learning opportunities the duration tend to be more realistic vs pessimistic. Another way that we use time buffers is that we build our schedules on a 5 day single shift schedule, so if a craft partner is falling behind their commitment they can work later hours and or they can work on Saturday. These are not always feasible as there may not be an allowance for overtime work premiums. If every trade partner carries the buffer we tend to have production plans that exceed our phase durations. One discussion that I have been involved in is that the General Contractor should hold the buffer and make it visible in the pull plan for all to be aware. This is very hard for many to do as it hasn’t been done before a lot and requires trust among the partners.
If we trust our craft partners and empower them with information then they will work with us to help the project out. This is a different way of working than what has been done for thousands of years in the construction industry. Not only do we have to be open and honest with our craft trade partners, we also have to be open with our design partners and the owner of the project. We can explain our methodology on which buffers we are using to manage which risk, which shows our expertise in managing projects. By engaging everyone in the value stream we can turn over great projects to great clients.