How to Realize Value from Conducting a Plus/Delta Evaluation

Plus/Delta: The Tool That Gets Meetings Better — When It Is Used Correctly

No competent builder would choose a hammer to drive a screw. Everyone in construction understands that choosing the right tool matters. And using it correctly with actual understanding of its purpose and capability is what separates a result from a damaged surface. This principle is as true of facilitation tools as it is of construction tools. And Plus/Delta is a facilitation tool that the Lean construction community uses constantly and understands incompletely.

Most teams run a Plus/Delta at the end of a meeting by asking “any plusses?” and “any deltas?” collecting a few answers, and moving on. They think they are doing continuous improvement. They are actually going through the motions of it while producing almost none of the value the tool was designed to deliver. This blog is about what Plus/Delta was actually designed to do and how to use it in a way that produces genuine meeting improvement.

Where Plus/Delta Came from and Why It Matters

In the 1970s, Michael Doyle and David Straus published a book called How to Make Meetings Work. As architects, they had spent years in design and construction projects, watching the conflicts and inefficiencies that characterized most professional meetings. They decided to find out what was actually going wrong. Their method was simple: they asked people across many different contexts what went wrong in their meetings.

The answers were remarkably consistent. People did not know why they were meeting or what the meeting was supposed to accomplish. There was no agenda or time allocation. Roles and decision-making authority were unclear. Someone dominated or went off track. Ideas were captured inconsistently or not at all. Action items were not assigned or followed through. The level of detail was wrong either too granular or too high-level, moving too fast or stuck.

Here is the insight Doyle and Straus drew from that pattern: none of those problems were about what the meeting was about. All of them were about how the meeting was planned and run. They called this condition process blindness, the failure to see that meetings have a process dimension that is separate from their content dimension, and that the process dimension is what determines whether the content accomplishes anything. The cure was process awareness, supported by a designated neutral facilitator whose job was to manage the meeting process rather than the meeting content.

The Plus/Delta emerged from this work as the Check step in the PDCA cycle applied to meeting process improvement. W. Edwards Deming, whose work on Total Quality Management was influencing organizations everywhere at the same time, had established that you cannot improve a process you cannot measure. Doyle and Straus applied that principle to the meeting process itself: plan the meeting, run the meeting, check how the process worked, act on what could be improved. Plus/Delta is the Check. The improvement at the beginning of the next meeting is the Act.

LCI founders Glenn Ballard and Greg Howell attended facilitation skills training at the firm Doyle and Straus founded and brought Plus/Delta along with many other best practices into the Lean construction community. That is where the tool came from. And it is what gets lost when teams use it as a routine sign-off question rather than as a genuine process improvement mechanism.

The Problem with How Most Teams Use It

“Any plusses? Any deltas?” asked to a tired group at the end of a long pull planning session or weekly work plan meeting produces generic feedback about the content of the discussion “that was a good meeting,” “we covered a lot of ground,” “we ran long on item three.” This is not process improvement. It is an opinion poll about how people felt.

The original intent of Plus/Delta is to evaluate the meeting process, specifically, whether the process design served the meeting’s purpose and what could be done differently in the next meeting to make the process work better. Plusses about what worked in the process. Deltas about what in the process could be improved. Not what the content was, but how the meeting was planned and run.

When Plus/Delta is disconnected from the meeting process, teams lose the feedback loop that would make their meetings progressively better. They run the same kind of meeting the same way, encounter the same friction, collect the same vague responses, and file them nowhere. The tool is present. The improvement is absent.

How to Use Plus/Delta Effectively

The quality of a Plus/Delta is determined by the quality of the questions. Generic questions produce generic answers. Specific questions about the meeting process produce specific, actionable feedback.

Start by identifying the critical success factors for the kind of meeting you just ran. What would have made this meeting great? For a weekly work plan meeting, critical success factors might include: clarity of commitment from each trade, productive use of the time allocated to each zone or phase, honest identification of roadblocks rather than optimistic assumptions, and clear ownership of each action item. For a pull planning session, they might include: genuine trade partner engagement throughout the backward pass, confirmation of handoff logic from zone to zone, and the team leaving with a shared understanding of the sequence they committed to.

Then design the Plus/Delta questions around those specific success factors. Not “what worked?” but “how did we do at making sure every trade partner declared their handoffs honestly?” Not “what could be better?” but “where did we lose time in the sequence, and what in the process produced that?” Specific questions produce answers that lead somewhere.

Vary the format. Ask for feedback on sticky notes rather than through open verbal response. Suggest a two-minute paired discussion to generate one improvement suggestion per pair before the whole group shares. Create and use a Great Meetings Checklist that holds the success factors visible and audits against them at the end of each session. If feedback from the previous meeting’s Plus/Delta produced a change, put that change on a flipchart at the start of the next meeting and check back at the end: did the change produce the improvement we expected?

Here are the signals that Plus/Delta is being used as a genuine improvement tool rather than a ritual:

• The questions asked are specific to the meeting’s process design, not about the content of the discussion.
• Feedback from previous Plus/Deltas visibly influences how the next meeting is structured.
• The facilitator tracks changes over time and the meeting format improves measurably from session to session.
• Trade partners and team members give honest feedback rather than polite agreement because they have seen the feedback used.
• The meeting’s critical success factors are visible and shared before the meeting begins, so the Plus/Delta at the end can measure against them.

The Most Important Commitment

All of this only works if the meeting leader is genuinely committed to using the feedback. A Plus/Delta run without follow-through is worse than no Plus/Delta at all, it signals to participants that their input is collected but not valued, which is more demoralizing than not being asked in the first place. If the team gives the same feedback three meetings in a row and nothing changes, they will stop giving feedback. The ritual will continue and the improvement will stop.

The actions of the meeting leader demonstrate either commitment to excellent meetings or the absence of that commitment. The tool will not do the work on its own. The leader’s decision to actually read the feedback, adjust the process, and track whether the adjustment produced improvement is what turns Plus/Delta from a meeting habit into a genuine continuous improvement cycle.

At Elevate Construction, every meeting from the strategic planning session to the foreman huddle to the training event has a process design that can be evaluated and improved. The retrospective at the end of the Super PM Boot Camp runs a structured Plus/Delta with specific questions about what served the learning objectives and what should be adjusted for the next cohort. The feedback is read, the improvements are made, and the next iteration is better because of it. If your project needs superintendent coaching, project support, or leadership development, Elevate Construction can help your field teams stabilize, schedule, and flow.

Plus/Delta done right makes every meeting better than the last. Done wrong, it is a question asked into the air at the end of a long day, producing nothing durable and consuming everyone’s time. Be purposeful. Ask the right questions. Use the feedback.

On we go.

Frequently Asked Questions

What is Plus/Delta and what was it originally designed to do?

Plus/Delta is a meeting process improvement tool developed by Doyle and Straus in the 1970s. It was designed as the Check step of the PDCA cycle applied to meeting process, evaluating whether the meeting’s process design served its purpose and identifying specific improvements for the next session.

Why is the standard “any plusses, any deltas?” approach insufficient?

Because generic questions produce generic answers about how people felt, not about what in the meeting process worked or failed. Process improvement requires process-specific feedback, which requires process-specific questions.

What is process blindness and how does Plus/Delta address it?

Process blindness is the failure to see that meetings have a process dimension, how they are planned and run that is separate from their content. Plus/Delta creates process awareness by explicitly evaluating the process at the end of each session and generating improvements for the next one.

What makes a Plus/Delta question effective?

Specificity. Questions tied to the meeting’s identified critical success factors produce answers that lead to specific, actionable changes. “How did we make sure every trade partner declared their handoffs honestly?” produces useful feedback. “What worked?” almost never does.

What happens when Plus/Delta feedback is not acted on?

Participants stop giving honest feedback because they have learned it is not used. The ritual continues and the improvement stops. The tool becomes theater rather than a genuine improvement mechanism.