Holding Start Dates

Why Moving Trades Forward Extends Your Duration (And How Holding Start Dates Actually Finishes Projects Faster)

Here’s the mistake that extends construction durations while making superintendents feel productive: moving successor trades forward when predecessor trades finish early, thinking you’re being efficient by eliminating gaps in the schedule. Your framing crew finishes Zone 3 on Thursday instead of Friday. You immediately call the MEP trade and say “great news, you can start Friday instead of Monday we’re ahead of schedule!” You feel like a hero. You’re accelerating the project. You’re being proactive. But here’s what you actually just did: you enacted the law of the effect of variation which states that the more variation you create or allow to impact work, the longer the overall duration and throughput time become. You didn’t accelerate the project. You extended it.

Let me explain what actually happens when you move that start date forward arbitrarily. Now the MEP trade has to move up their concrete pours or reroute their crews who were scheduled for different work Friday. Now you have to prioritize different crane picks to support the accelerated sequence. Now you’re rerouting field engineers who had other layout scheduled. Now you’re recalling inspectors who weren’t planning to be there until Monday. I’m not even going to waste your time I could probably easily get another 30 things off the top of my head that have to change. And most of the time it’s hundreds of things that change when you arbitrarily move one start date. Every single one of those changes creates variation. And variation extends duration. You thought you were saving three days by moving the start forward. You actually added two weeks to overall completion through the chaos you created.

Here’s what I’m going to talk about: holding start dates in Takt systems. That might seem like an interesting topic maybe you’re wondering where this came from. But I want you to know that Takt, the Takt principle where we move from zone to zone on Takt time with leveled crews and leveled zones, is our first guiding principle. And understanding why we hold start dates instead of arbitrarily moving them forward is critical to making Takt work. This connects to stability, to respect for people, to preventing push-rush-panic cycles, and to actually finishing projects faster through rhythm instead of chaos. So, let’s talk about why superintendents keep making this mistake, what actually happens when you move trades forward outside their planned starts, and how holding start dates finishes projects sooner than constantly accelerating them.

Understanding Takt and Pull Principles (And Why Pull Alone Is Dangerous)

Let me start by explaining the foundation so we’re all clear. Takt the Takt principle is where we move from zone to zone on Takt time with leveled crews and leveled zones. That’s our first guiding principle for flow. The second principle is pull. But here’s where most people get this wrong and why it becomes dangerous.

In the industry, when people teach pull, they teach it like trades only move forward when the trade in front of them finishes. And that is dangerous because you don’t have target times and you’re not aligning what I call your in-zone cycle time to overall Takt time. It also adds an unnecessary amount of variation. Pure pull without Takt time creates chaos because every finish time becomes a new start time, and you’re constantly adjusting instead of maintaining rhythm.

What we have to do on construction projects is level the zones by work density, and then level the crew durations and how they’re packaged so they can flow evenly together going the same speed, the same distance apart, working on a Takt time with cadence. When I say Takt time, that means the rhythm where a trade starts from zone to zone. And actually, the other trades begin after that first contractor for the most part in a leveled single train that has a rhythm to it.

The Focus Is Start-to-Start and End-to-End

The focus is the start-to-start lag and the end-to-end alignment. That’s really important because it’s not about when individual activities finish it’s about maintaining the rhythm between starts and ensuring the overall completion aligns to milestones. And here’s the typical pattern we see. A superintendent inside the general contractor will be like “oh, trade partner, you finished on Thursday. Let’s move your successor contractor up to Friday” and immediately increase variation.

And the problem is this violates multiple lean principles simultaneously. Not only should we hold stability when it comes to cleanliness, safety, and organization in construction, not only should we eliminate the eight wastes and overburden and unevenness, not only should we keep things clean through 5S, but we should also be very standardized and stable when it comes to our start dates and our time. This is stability applied to schedule, not just to workspace conditions.

Why Holding Start Dates Matters: The Law of Effect of Variation

Why? The reason is because if you move a trade forward outside of their will meaning you force them, not that they’re asking to start early or able to start early, but outside of the trade wanting to do it or being prepared to do it you cause variation. And the law of the effect of variation says that the more variation you create or is created or occurs or impacts work, the longer the overall total duration or the longer the overall throughput time.

Let me say that again because it’s critical: more variation = longer duration. Not shorter. Longer. Even when the variation seems like acceleration, it extends duration through chaos.

So if you’re like “hey, we’re going to move the concrete placement up” or “we’re going to change direction,” now you have to move up concrete delivery. Now you have to reroute their crews who were scheduled elsewhere. Now you have to make sure you’re prioritizing these certain picks with the crane, disrupting the crane schedule for other work. Now you’re rerouting the field engineers who had other layout planned. Now you’re recalling the inspectors who weren’t scheduled to be there yet.

I could probably easily get up to another 30 things off the top of my head that take time and cause chaos. And most of the time it’s in the hundreds of things that change when you arbitrarily move one start date. The law of the effect of variation extends durations and throughput times. Every single time. No exceptions.

The Pattern That Makes This Worse: Authority Without Understanding

The problem is we’ve been teaching superintendents for a long, long time to just walk out in the field and change things. And they think because they have authority that they’re doing a good job. But they’re actually only enacting the law of the effect of variation. They’re only hurting the job. They’re only making the project take longer. It’s so disappointing to watch because these are good people with good intentions trying to accelerate projects, and they’re doing the exact opposite through variation they’re creating.

The College Assignment Analogy: Why This Creates Sandbagging

Let me give you an analogy from a human standpoint that shows why this destroys trust and creates sandbagging. Let’s say you’re going to turn in an assignment and you’re in university and your assignment’s due Sunday night. You turn it in on Thursday to the professor, excited about getting it done early. You’re also excited that you have time to clean your room or your dorm, go out to the lake with friends, maybe go on a date, whatever. Maybe go see your family.

And your professor says “great job, great job. Now your next assignment is moved up and it starts Friday and it’s due next Friday.” How many times do you think that person would turn an assignment in early after that experience? And how do you think they would feel about their professor?

Now we see the effect of sandbagging and why trades don’t trust us in those situations. If finishing early gets punished with immediate additional work without any buffer or rest or preparation time, trades will never finish early again. They’ll sandbag. They’ll stretch the work to fill the time. They’ll protect themselves from your “efficiency.”

The Human Cost: Overburdening People

And we also see that you’re overburdening people. We’ve got to have a buffer at the end of our cycle times to finish properly, to punch right then and there when the crew is present with tools and materials, to train and develop people, to clean and organize the zone through 5S, to demobilize properly from zones. This buffer time isn’t waste it’s essential capacity for finishing as you go and maintaining standards.

When we rush and push and panic and move up the start dates arbitrarily outside of the trade wanting to do it, not only are we enacting the law of the effect of variation, not only are we overburdening people (that’s muri in Japanese overburden), but we are failing to finish properly. We are putting them in a cycle of push, rush, and panic that they will never properly recover from. It is the most toxic thing in construction.

What Actually Happens When You Move Start Dates Forward

Let me walk through what actually happens in detail when a superintendent moves a trade forward thinking they’re being efficient. Predecessor finishes Thursday instead of Friday. Super calls successor trade: “Good news, you can start Friday instead of Monday.”

The Cascade of Changes That Follow One Moved Start Date

• Crew Mobilization: Trade has to reroute crews who were scheduled for different work Friday. Those other projects now have gaps. Those crews lose preparation time for this project.
• Material Delivery: Materials were scheduled to deliver Monday morning. Now you need Friday delivery. Supplier has to expedite. Delivery sequence for other projects gets disrupted. Costs increase.
• Equipment Coordination: Equipment was scheduled to arrive Monday. Now you need it Friday. Rental company has to reroute. Other projects waiting for that equipment get delayed.
• Information Availability: Submittal approvals, RFIs, or design clarifications that were scheduled to resolve by Monday now need to be resolved by Friday. Office team scrambles. Quality suffers.
• Inspection Scheduling: Inspector was scheduled Monday. Now you need Friday. Inspector has other projects Friday. You either wait (negating your acceleration) or proceed without inspection (creating rework risk).
• Predecessor Finish Quality: Predecessor was going to use Friday to complete punch items and clean handoff. Now they don’t have that buffer. Successor pulls into a zone that’s 95% complete instead of 100%. Coordination conflicts and cleanup delays follow.
• Crane Schedule: Crane picks were planned for Friday supporting different work. Now you need crane support for the accelerated trade. Other work gets delayed waiting for crane availability.
• Field Engineering: Layout and verification were scheduled Monday morning. Now field engineers have to do it Friday. Whatever they were planning Friday gets pushed. Other trades waiting for that layout get delayed.
• Safety Planning: Pre-task plan was going to be done Monday morning with proper crew preparation huddle. Now it’s rushed Friday. Safety quality decreases. Incident risk increases.
• Supply Chain Ripples: Every supplier, subcontractor, and logistics partner downstream from this trade now has variation injected into their schedules. They all have to adjust. Chaos multiplies.

Count those disruptions. That’s ten major categories, each with multiple subcategories. Easily 30-50 specific impacts from moving one start date forward by three days. And every single one of those impacts creates variation that extends overall duration even though you thought you were accelerating.

When Simulated or Done in Real Life: Holding Finishes Sooner

When we play simulations, when we do this in real life, if you have Takt time that is enabling your milestone and you have buffers at the end of your pace-setting train of trades in a phase, why not just hold the start dates? What are you going to lose?

Anytime we simulate this, anytime we do this in real life, you actually end up finishing sooner by holding start dates than by constantly moving them forward. The stability enables flow. The rhythm prevents chaos. The buffers enable finishing as you go. And finishing sooner happens through system stability, not through constant acceleration that creates variation.

What Holding Start Dates Is Not

Holding start dates is not complacency. It’s not laziness. And it’s not sandbagging. It’s good practice because we must make sure we’re on a rhythm. We’ve got to maintain stability. And we can’t overburden people and put them into a push cycle and into a downward productivity spiral.

Let me be absolutely clear about this because I know some superintendents are thinking “but Jason, if I don’t push, nothing will get done. If I don’t constantly accelerate, we’ll fall behind.” That’s not how production systems work. That’s not how flow works. That’s not how human performance works.

The Downward Productivity Spiral

When you constantly push, rush, and panic, you create a downward productivity spiral where each acceleration creates variation, variation creates chaos, chaos creates mistakes, mistakes create rework, rework creates delays, delays create more panic, more panic creates more pushing, and productivity collapses. You cannot push your way to higher productivity. You can only flow your way there.

The Supply Chain Impact

The other thing people miss is you have aligned information and material and resource supply chains. So, you start moving your start dates around not only do you affect the work on site and everything I’ve talked about applies to the work on site, but you also now have affected the supply chains. Materials that were scheduled to deliver Monday now need Friday delivery. Equipment rental schedules get disrupted. Supplier production schedules that were aligned to your rhythm now have to adjust. Logistics partners who coordinated deliveries around your published schedule now face conflicts.

It’s so, so detrimental. The ripple effects extend far beyond your job site into every supplier and partner’s operations. And they all have other customers besides you. Your variation becomes their chaos. Your “efficiency” becomes their nightmare. And eventually they build buffer into their commitments to you because they know you’ll change start dates arbitrarily, which means your future schedules get longer to accommodate the variation you keep creating.

How to Actually Use Buffers in Takt Systems

So what do you do with the time when predecessor finishes early? You use the buffer for its intended purpose: finishing as you go. The predecessor uses Thursday-Friday to complete punch items right then and there when crews are present with tools and materials. They clean and organize the zone through 5S. They do proper handoff verification with the successor trade scheduled for Monday. They demobilize equipment properly. They conduct training or safety reviews. They prepare for the next zone.

The buffer isn’t wasted time. It’s essential capacity for maintaining standards while flowing. And when Monday comes, the successor trade pulls into a zone that’s 100% complete, clean, organized, and ready. No cleanup required. No punch items discovered. No coordination conflicts. Just clean handoff enabling immediate productive work.

When Trades Ask to Start Early (The Exception)

Now let me address the exception because I know someone will ask. What if the trade wants to start early? What if they’re asking to move forward, not being forced?

Even then, be very careful. Ask why they want to start early. Often, it’s because they’re trying to make up time on another project and your project becomes the adjustment valve. That’s their variation being injected into your system. Or they see an opportunity to get ahead but haven’t thought through all the coordination impacts I described above.

The better approach: acknowledge they could start early, recognize the buffer they created, and ask if they’d prefer to use that buffer for anything that would help them on future zones. Additional training? Extra finishing time? Equipment maintenance? Preparation for a more complex zone ahead? You’re respecting their capability while protecting system stability.

If they genuinely want to start early and all coordination can be maintained without creating variation, fine. But make it the exception, not the rule. And never force it.

The Difference Between Takt with Held Starts vs CPM with Constant Acceleration

Here’s the fundamental difference in mindset. CPM thinking says “any gap in the schedule is waste, eliminate all gaps, constantly accelerate.” Takt thinking says “rhythm creates flow, buffers enable finishing, stability produces speed.” CPM optimizes for utilization keep everyone busy. Takt optimizes for throughput finish the project faster through flow.

Ironically, CPM’s focus on eliminating gaps and constantly accelerating creates so much variation and chaos that projects take longer. Takt’s focus on holding rhythm and protecting buffers creates stability that enables projects to finish faster. The math proves this every time we simulate it. The field results prove this every time we implement it properly.

Resources for Implementation

If your project is stuck in constant acceleration mode where superintendents keep moving trades forward thinking they’re being efficient but duration keeps extending, if you want to implement Takt systems that actually finish faster through held starts and protected rhythm, if you need help understanding how buffers enable finishing instead of representing waste, Elevate Construction can help your teams shift from push-based acceleration to flow-based stability that completes projects sooner through system discipline instead of heroic effort.

Building Systems That Flow Through Stability, Not Push Through Variation

This connects to everything we teach at Elevate Construction about creating production systems that enable people instead of overburdening them. Holding start dates isn’t complacency it’s the discipline that enables flow. Moving trades forward arbitrarily isn’t efficiency it’s enacting the law of effect of variation that extends duration. Buffers aren’t waste they’re essential capacity for finishing as you go and maintaining standards.

The college assignment analogy shows why arbitrary acceleration destroys trust and creates sandbagging. The supply chain impacts show why your local “efficiency” becomes chaos for everyone depending on your schedule. And the simulation results prove what happens in real life: holding start dates finishes projects sooner than constantly moving them forward because stability enables flow while variation creates chaos.

A Challenge for Superintendents

Here’s the challenge. Stop thinking authority to change schedules means efficiency. Start understanding that every start date change creates variation, and variation extends duration regardless of intent. Stop moving trades forward when predecessors finish early thinking you’re accelerating. Start using those buffers for finishing as you go so handoffs are clean and complete.

Implement Takt systems with held start dates. Level your zones by work density. Package your trade durations to Takt time. Maintain rhythm between start-to-start lags. Protect buffers at the end of pace-setting trains. Use those buffers for punch, training, cleaning, proper demobilization not for arbitrary acceleration that creates chaos.

When predecessors finish early, celebrate the buffer they created. Use it for finishing as you go. Verify handoffs will be 100% complete. Don’t punish early completion by immediately moving successor trades forward without preparation. Trust the rhythm. Protect the stability. And watch what happens when flow replaces push.

Track the results: zones handed off 100% complete instead of 95%, successor trades pulling in without cleanup or constraints, supply chains aligned to predictable rhythm instead of constantly adjusting, trades trusting the schedule and not sandbagging, overall duration shorter through stability not acceleration, workers not overburdened by constant push-rush-panic cycles.

As Taiichi Ohno taught us: stability must come before improvement. You cannot improve chaos. Held start dates create stability. Arbitrary acceleration creates chaos. The choice determines whether your project flows or fights its way to completion. Choose stability. Choose rhythm. Choose holding start dates so your project can actually finish faster through flow.

On we go.

Frequently Asked Questions

Won’t holding start dates make projects take longer?

No. Simulations and real-world results prove holding start dates finishes projects sooner because stability enables flow while constant acceleration creates variation that extends duration through chaos and rework.

What about when trades finish early?

Use the buffer for finishing as you go punch items, cleaning, 5S, training, proper demobilization. The buffer isn’t waste; it’s essential capacity for maintaining standards while flowing.

Isn’t moving trades forward when possible just being efficient?

No. Each moved start date creates 30-50 coordination impacts (crew mobilization, materials, equipment, inspections, etc.). The variation extends overall duration even though it seems like acceleration.

What if the trade asks to start early?

Ask why. Often they’re making up time on another project, which injects their variation into your system. If genuinely prepared and coordination maintains, consider it but make it exception, not rule.

How does this relate to pull systems?

Pure pull (start when predecessor finishes) without Takt time is dangerous because it adds variation. Takt + held starts create rhythm. Pull provides handoff verification, not arbitrary acceleration triggers.