Steadiness & Flow – An Excerpt from Elevating Construction Superintendents

Red Team Finished In 26 Weeks With 380 People And Blue Team Finished In 21 Weeks With 280 People Doing Same Work Because Variation Destroys Throughput

Creative Trades game. Seven participants sit around table. Each represents contractor for different scope: concrete steel facade and so on. Thirty-five chips on table represent 35 pieces of work that must be completed to finish project. Goal is to pass all chips through to last contractor as quickly as possible to simulate completion of work on project. To complete their work players roll die and pass that number of chips to person next to them. If someone rolls six but only has one chip at their station they can only send one chip forward. If they have six chips and roll one they can only move one chip. When everyone has rolled that represents one week of work and process is repeated for as many weeks necessary to move all chips to end. Often this game is played with different teams competing with each other to be team to finish their work in fewest number of weeks.

Red team got all 35 chips to end in 26 turns. When you tally number of workers on site you get 380. Maximum material inventory at any one location was 10. So in 26 weeks red team moved 35 units of work down line with 380 people and material inventory level of 10 units per week. Pretty good. How did blue team do? They completed work in 21 weeks with 280 people and maximum material inventory buildup of just 5 in given week. That means blue team was 5 weeks ahead of schedule with 100 fewer people on site and half material on site. How did they manage that?

Tricky secret is that red team had regular six-sided die with numbers ranging from one to six. Blue team had die that could only roll fours threes and twos. Week with normal die would be something like 6 5 5 2 2 1 and would represent attempt to move quickly at first followed by slowdown because of interruption and eventually ending up stuck. Week with blue team’s die might look like 4 3 4 3 2 2. This is synonymous with concept of maintaining flow of work. Flow has very little variation. When that variation is eliminated chips or work can flow from one end to another without getting held up by overwhelming rush from rolling six or painful crawl of one.

Cost comparison proves variation destroys projects. Twenty-six weeks with 380 workers is 380 people at $55 per hour at 40 hours week at 26 weeks equals $21.7 million. Twenty-one weeks with 280 workers is 280 people at $55 per hour at 40 hours week at 21 weeks equals $12.9 million. That is $8.8 million difference. This ratio can be scaled for whatever size project we are talking about. Differences in man-hours spent in waste because of lack of flow. Pushing literally destroys projects and our industry. Supers must protect us from this. If your project needs superintendent coaching, project support, or leadership development, Elevate Construction can help your field teams stabilize, schedule, and flow.

What Movement Versus Production Actually Means

Before making lesson explicit let us reflect on current state of our industry. We often hear people say: we need to get out of ground fast when we can influence fewer number of contractors. This is correct. We also hear that we need to be aggressive with complex and unknown areas and scopes on our projects. This is also correct. Sometimes though well-meaning folks will apply both of those concepts to entire project and say things like: advance schedule whenever possible. I want all my materials here now. Just bring it. I am pusher. Keep pushing everything you can for schedule.

These people are trying to roll sixes in parade of trades which will later cause mess of ones. Consider this: what if we told superintendent to slow down little and keep steady flow and even pace? What would he say? He might say: we know absolutely nothing about construction and should go get another job. And yet data shows he will finish in 26 weeks with 380 people on site with material inventory of 10 like red team in Creative Trades.

This happens because people think movement equals production which is not the case. All this movement is actually waste. People start pushing and creating variation because it makes them feel good. It gives impression of progress but it requires twice as much material 100 more people and 5 more units of material inventory in week. What happens when superintendent will not keep flow in schedule and hold dates? If you are trade partner how would you react? You would possibly keep more people on site and most definitely keep more materials on site.

What happens when materials pile up on site? You guessed it. Production slows down. Everything slows down because part of our workforce is dedicated to managing moving inventorying fixing replacing reordering and organizing materials.

The Factory Throughput Lesson That Proves Variation Destroys Systems

Imagine factory with assembly line that produces certain number of finished items every hour. Throughput is rate at which factory can process raw materials into finished items. Say you have four machines in factory that work together to produce final finished product. Items need to be moved from one machine to next for that machine to do its part in process. First machine can work on four items per hour. Second at two items per hour. Both third and fourth machines produce four items per hour. What is throughput of system per hour? Did you say two?

Now what could we do to get all machines working at same rate? Speed up two-part per hour machine. That is correct. We can either add another machine or replace it with faster one. What would throughput of this system be then? Did you say four? That is correct. But what if we did not speed up two-part per hour machine? What else could be done to get everyone working in same rate? Yes that is correct. We could slow down fours and get everyone working at throughput of two parts per hour.

Here is moment. You said throughput of first example where we had all machines working at full efficiency even though they were going different speeds was two. This may surprise you but it is likely going to be 1.25 or 1.5 finished items per hour. Consider what happens between first and second machines. Inventory of materials begins to pile up. Manpower is then allocated to manage material inventory. Space in factory diminishes. People who would otherwise be running machines are now managing machines and material inventory. Workers down line are waiting and more resources are needed to manage materials on third and fourth machines. Waste increases and speed of system decreases. Therefore throughput of 1.5 or fewer finished items per hour instead of two.

That is throughput. They would have been better off to increase two-part per hour machine to four-part per hour machine or slow everything down to two. That would at least have throughput of two parts per hour. When anyone on site says: work everywhere at full efficiency. Keep pushing. Bring all materials here now. Do not slow down anything. I want workers working everywhere on site with no empty areas. All they are doing is slowing down speed of production by increasing material inventory and creating lot of wasted jobs for people who would otherwise not be needed on that site.

Why? Because we needed flow. What we got was variation. If this was parade of trades we needed to roll consistent threes and fours instead of sixes and ones.

When To Push And When To Flow

Answer is not to push all time. Ideal is somewhere in between. Anything on site that can be made to flow should. If we are coming out of ground or have complex area on site with high-risk unknowns those may be good reasons to accelerate. Point is that pushing comes at risk and flow will always reduce materials manpower mistakes and time it takes to do something. So if you can create flow do it. If you must pull area know consequences and do it only if you must put work in place early to vet mistakes early. But for no reason should you push on site and create variation. Do not roll sixes and ones when you can roll threes.

Art of Takt means artfully taking advantage of opportunities to plan prepare and move strategically. If you hear someone ask to create variation in schedules and flow be skeptical. If you hear folks ask for increase in material inventory give it second look. We want to create stable environments keep workers installing work they plan for day or week and have plan for everything.

Important reflection is cost associated with it as well. If you compare just in Creative Trades example cost difference between red team and blue team you get $8.8 million difference. This ratio can be scaled for whatever size project we are talking about. Differences in man-hours spent in waste because of lack of flow. Pushing literally destroys projects and our industry. Supers must protect us from this.

Signs You Are Creating Variation Instead Of Flow

Watch for these patterns that signal you are rolling sixes and ones instead of threes and fours:

• Superintendent says advance schedule whenever possible or I want all materials here now or just bring it or I am pusher or keep pushing everything creating variation that requires twice as much material 100 more people 5 more units of inventory slowing production through waste
• Trade partners keep more people on site and more materials on site because superintendent will not hold dates or keep flow creating inventory buildup where workforce dedicates time to managing moving inventorying fixing replacing reordering organizing materials instead of installing work
• Workers working everywhere on site with no empty areas sounds efficient but actually slows throughput because resources spread too thin creating stacking waiting trade conflicts coordination failures proving movement does not equal production
• Factory machines running at full efficiency with different speeds (4-2-4-4 items per hour) produces 1.25-1.5 items per hour instead of 2 because inventory piles up between machines consuming manpower space resources proving individual efficiency destroys system throughput
• Project finishes on time but at massive expense to owner trades and finances burning through budget with excessive manpower material inventory rework because pushed instead of flowed proving finishing on time does not mean finishing well
• Team celebrates early completion without examining cost showing finished 5 weeks early but spent $8.8 million more than necessary because created variation instead of maintaining flow destroying profitability while claiming success

These are signs you are pushing when you should be flowing. Rolling sixes and ones when you should roll threes.

The Cost Of Pushing Versus Flowing

Many supers will say: I have been doing this for over 30 years and have always finished on time. This is correct but at what expense to project owner and trades and their finances? It deserves deeper look and further consideration. When you compare red team versus blue team in Creative Trades game you see what pushing costs.

Red team: regular die rolling 1-6. Finished in 26 weeks. Required 380 workers. Maximum inventory 10 units. Total cost: 380 people at $55 per hour at 40 hours week at 26 weeks equals $21.7 million. Blue team: limited die rolling 2-4. Finished in 21 weeks. Required 280 workers. Maximum inventory 5 units. Total cost: 280 people at $55 per hour at 40 hours week at 21 weeks equals $12.9 million.

Difference: Blue team finished 5 weeks earlier with 100 fewer people with half inventory at $8.8 million less cost. Same work. Same chips moving through system. Only difference: variation versus flow. Red team tried to roll sixes creating massive rushes followed by painful crawls of ones creating inventory buildup resource waste coordination chaos. Blue team rolled consistent threes and fours creating steady flow eliminating inventory buildup maintaining rhythm protecting throughput.

Scale this to any project size. Hundred million dollar project. Two hundred million dollar project. Billion dollar project. Ratio holds. When you push instead of flow you spend millions more. Require hundreds more workers. Create massive inventory levels. Extend duration. Destroy profitability. All while thinking you are being efficient aggressive productive. When reality: you are being wasteful chaotic destructive.

This is why flow matters. Not soft principle. Not nice-to-have. Not theoretical. Mathematical principle. Proven through Creative Trades game. Proven through factory throughput calculations. Proven through cost comparisons. Proven through projects that maintain rhythm versus projects that push randomly. Flow shortens durations. Flow decreases costs. Flow respects workers. Flow creates balance for families. Pushing destroys all of that.

What Happens When Superintendent Won’t Hold Flow

What happens when superintendent will not keep flow in schedule and hold dates? If you are trade partner how would you react? You would possibly keep more people on site and most definitely keep more materials on site. What happens when materials pile up on site? Production slows down. Everything slows down because part of workforce is dedicated to managing moving inventorying fixing replacing reordering and organizing materials.

Consider factory example again. First machine produces 4 items per hour. Second machine produces 2 items per hour. Third and fourth machines produce 4 items per hour. If you run all machines at full efficiency what happens? Inventory piles up between first and second machines. Four items per hour coming in. Only two items per hour going out. Inventory grows by 2 items every hour. After 8 hours: 16 items piled up. After 40 hours: 80 items piled up. Space consumed. Manpower allocated to manage inventory. People who should run machines now managing piles. Workers down line waiting because second machine cannot keep up. Resources needed to manage materials on third and fourth machines. Waste increases. Speed decreases. Throughput drops to 1.25-1.5 items per hour instead of 2.

Same thing happens on construction site. Superintendent says: bring all materials now. Get everyone working everywhere. Push schedule whenever possible. Advance dates randomly. Do not hold rhythm. What happens? Materials pile up. Deliveries uncoordinated. Inventory levels spike. Space consumed. Workers spend time managing moving protecting materials instead of installing. Coordination breaks down because trades stacked. Sequence interrupted because materials blocking access. Quality suffers because rushing. Safety incidents increase because chaos. And throughput drops. Project takes longer. Costs more. Burns out workers. Destroys families.

All because superintendent would not hold flow. Would not keep rhythm. Would not protect steady pace. Tried to roll sixes and ones instead of threes and fours.

The Challenge

Stop saying advance schedule whenever possible or I want all materials here now or just bring it or I am pusher or keep pushing everything. Start recognizing these statements create variation requiring twice as much material 100 more people 5 more units of inventory slowing production through waste. Stop thinking movement equals production celebrating activity as progress. Start recognizing all this movement is actually waste and impression of progress requires massive expense destroying profitability. Stop running all machines at full efficiency with different speeds thinking individual efficiency creates system efficiency. Start recognizing inventory piles up between machines consuming manpower space resources dropping throughput from 2 to 1.25-1.5 proving individual efficiency destroys system throughput. Stop saying I have been doing this for 30 years and always finished on time as if that proves effectiveness. Start asking at what expense to project owner trades and their finances recognizing finishing on time but spending $8.8 million more than necessary is not success. Stop pushing when you should be flowing creating variation when you should create rhythm. Start recognizing anything on site that can be made to flow should flow and pushing comes at risk that flow eliminates.

As Creative Trades game teaches: red team with regular die finished in 26 weeks with 380 people at $21.7 million. Blue team with limited die finished in 21 weeks with 280 people at $12.9 million. Difference: $8.8 million saved by eliminating variation and maintaining flow. Do not roll sixes and ones when you can roll threes and fours. Flow has very little variation. When that variation is eliminated work can flow from one end to another without getting held up by overwhelming rush from rolling six or painful crawl of one. Flow will always reduce materials manpower mistakes and time it takes to do something. Only flow will shorten durations. Only flow will decrease costs. Only flow will respect workers. Only flow will create balance for families. That is why we are so focused on it. If you can create flow do it. If you must pull area know consequences and do it only if you must put work in place early to vet mistakes early. But for no reason push on site and create variation. Art of Takt means artfully taking advantage of opportunities to plan prepare and move strategically. Create stable environments. Keep workers installing work they plan for day or week. Have plan for everything. Protect flow. Guard rhythm. Roll threes not sixes. On we go.

Frequently Asked Questions

What is Creative Trades game and what does it teach about flow?
Seven participants represent contractors passing 35 chips through system by rolling dice, red team with regular die (1-6) finished in 26 weeks with 380 people and $21.7M cost, blue team with limited die (2-4) finished in 21 weeks with 280 people and $12.9M cost, difference of $8.8M proving variation destroys throughput while flow creates efficiency.

Why does running factory machines at full efficiency actually slow throughput?
Four machines at 4-2-4-4 items per hour should produce 2 per hour but actually produces 1.25-1.5 because inventory piles up between first and second machines consuming manpower and space, people managing inventory instead of running machines, workers waiting, resources managing materials, waste increasing, speed decreasing proving individual efficiency destroys system throughput.

What happens when superintendent won’t keep flow and hold dates?
Trade partners keep more people on site and more materials on site, materials pile up, production slows down because workforce dedicates time to managing moving inventorying fixing replacing reordering organizing materials instead of installing work, coordination breaks down, sequence interrupted, quality suffers, safety incidents increase, throughput drops, project takes longer costs more burns out workers.

When should you push and when should you flow?
Flow anything on site that can be made to flow, if coming out of ground or have complex area with high-risk unknowns those may be good reasons to accelerate, but pushing comes at risk and flow will always reduce materials manpower mistakes and time, so create flow when possible, only pull area if must put work in place early to vet mistakes early, never push to create variation.

Why do people think movement equals production when it’s actually waste?
People start pushing and creating variation because makes them feel good gives impression of progress, but rolling sixes creates overwhelming rush followed by painful crawls of ones requiring twice as much material 100 more people 5 more units of inventory, all this movement is waste not production, flow eliminates this by rolling consistent threes and fours maintaining rhythm protecting throughput.