Scrum Pattern – Plus Delta Hash(PDH) Retrospective


The PDH retrospective is a retrospective format that is very efficient and fairly simple. Teams quickly generate discussion topics(Transparency) by listing the things that went well(plusses) and the things that should change(deltas) to make the team better in the upcoming Sprint. The team then has a chance to quickly vote on the discussion topics to help prioritize and order the discussions. With the discussion agenda quickly set, the team then sets about discussing the most important topics(Inspection) and develops action items(Adaptation) that allow the team to improve its Scrum implementation.

Possible Contexts

  • A team needs or wants a retrospective format that is very simple and/or efficient.
  • A team that has a very limited amount of time to execute a retrospective.
    • I personally encourage teams to use the entire Scrum time-box so long as the team thinks it is continuing to have valuable discussions. Having *retrospectives that are too short* is an anti-pattern.
      • I encourage brand new Scrum Teams to use twice the time-box for the first 3 retrospectives so that the team achieves a culture of improvement and self organization. Don’t forget the definition of “time-box,” though — your meeting doesn’t *have* to take 3 hours — that’s just the max!
  • A team that is of any size, but this pattern is very efficient for large teams.
  • A team that prefers discussion and solution seeking over free form discussion.

Situations where this pattern might not be a good fit

  • Teams that have done this retrospective format too many times and are bored with it.
  • Teams that do not have the needed supplies or tools to execute this format.
  • Teams where multiple members are working remotely (but see Variations section for a possible solution)


(This is probably obvious, but the number of votes and time-boxes can and should be adjusted to the team size, time allowed, etc)

  1. Review the Previous Retro Action Items
  2. Generate Ideas about what went well, and what changes to make.Have each team member stand in front of a whiteboard (or large post it note) and list:
    • At least 2-3 Plusses
      • Things they liked about the current Sprint.
    • At least 2-3 Deltas
      • Things they would like to see change.
    • Time-box this to a fairly short period of time (5-15 minutes). Extend the time period in small increments if people need more time. During the time-box, remind peoiple that that they are encouraged to put more than the minimum — anything that’s on their mind. These items will become the discussion topics. If the need arises (and I’ve found that it usually doesn’t), discourage people from looking at others’ lists until they are done. As much as possible, we want independent topic generation.
  3. Vote on the ideas to discuss and/or change.Hash Voting:
    • Now tell the team that they have 10 votes (you can adjust this of course, but it should be 5 at least) for Plusses and 10 votes for Deltas. Tell them to go around the room and put hash marks as their votes by topics they either a) want the team to discuss and/or b) that they agree with. They can place one vote on each topic or all of their votes on one topic. If they have questions about what something means, tell them to ask the author. Encourage them not to have the actual discussions yet, just to seek clarification of what the author meant by the topic. If they find similar topics and want to group them together as one topic, tell them to self organize to do that. Time-box this exercise to a fairly short period of time (5-10 minutes), and extend in very small increments if people need more time to vote or clarify/consoidate topics. Ideally, we really want to get people’s first instincts, so don’t allow too much time.
  4. Count and rank the discussion topics. Count the votes and rank the topics(count and rank Plusses and Deltas separately) with the most votes(1, 2, 3, 4, 5, etc). This will become the “ordered discussion backlog”.
  5. Discussion
    • Discuss Plusses
      • This usually takes very little time, but it is a chance to give each other attaboys and “I liked that too.” It also gives the team to reflect on the things that are going well, as a reminder to continue to do those things. You usually don’t need but about 5-10 minutes of discussion for those.
    • Discuss Deltas
      • Discuss the top ranked deltas, and have the facilitator monitor the discussions to make sure that they are fruitful. The facilitator should be sure to let the conversation go long enough to get to proposed action items and solutions. Each topic should end in an action item like the following:
        • Try something in the upcoming sprint.
          • Try a new approach
          • Change team working agreements
          • Change the definition of done
          • Some other thing to try
        • Take the discussion off-line into the upcoming sprint.
        • Agree to change nothing for one sprint and discuss it again at the next retrospective.
          • Another possible action item is, after discussing the topic, to keep things the way they are. I don’t like this kind of action item with important topics because it discourages trying new things. To me, a better solution is to try something for one Sprint and then retrospect again. A last ditch solution is to agree to keep things the way they are for one sprint and agree to definitely discuss it again in the next retro. If after two retros, there is no consensus on a suggested change, then it’s probably ok to go without an action item for that topic.
      • Each discussion should almost always end in an action item like the above.
  6. Make the agreed upon action items highly visible on your Scrum Board.


  • Remote Members strategy: For teams with remote members participating, consider a different setup where all members are on a conference call and simultaneously on a team wiki. Have each member create a wiki page for their suggested discussion topics. When voting, consider:
    • having the participants use their initials instead of hash marks to vote on the wiki page, OR
    • using the “secret ballot” strategy below.
  • Secret Ballot strategy: If the vote placing itself gets a little cagey for the team (people waiting to put their votes until the last second, in order to more strongly influence the top topics), consider having the team jot down their votes on a piece of paper privately, and then have the facilitator randomly go around the room asking team members to voice their votes (“I had 3 hash marks on topic ABC, 2 for topic GHI, and one for XYZ”).


  • Preferably a room where the Scrum team can have discussions where no else can hear
  • Several white boards and white board markers.
    • Large post it note sheets (~2′ x 3′) can be substituted if you don’t have enough whiteboard space.
  • A facilitator to explain the rules and keep things moving.

Scrum Guide

This pattern implements the required elements of Sprint Retrospectives in the Scrum Guide. The required elements basically boil down to:

  • Do a Retro every Sprint
  • The entire Scrum Team participates
  • Time-box it to 1.5 hours for a 2 week Sprint, 3 hours for a one month Sprint, etc
  • Discuss what happened in the Sprint “with regards to people, relationships, process, and tools.”
  • Discuss what should be changed in the next Sprint.
  • Make a plan to implement the changes in the next Sprint.
    • Changes should be within the Scrum Framework. They should not be changes to the framework itself.


I’ve seen the “Plus Delta” analysis and “Dot Voting” (Hash Voting is a variation of Dot Voting) in several publications and web sites, but I don’t really know the origin of the techniques. This pattern is one I’ve developed over time in coaching Scrum Teams and it seems universally successful. Having said that, don’t forget the Best Practice – Change Up Your Retrospective Format. If anyone knows of the true origins of any technique described above, feel free to email me at the address on the home page and I’ll be happy to post it here.

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