Project management ROPE estimate: realistic optimistic pessimistic equilibristic
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ROPE estimate


ROPE estimates are a way to do task timeline planning by using four perspectives:

  • R: Realistic estimate, based on work being typical, reasonable, plausible, and usual.

  • O: Optimistic estimate, based on work turning out to be notably easy, or fast, or lucky.

  • P: Pessimistic estimate, based on work turning out to be notably hard, or slow, or unlucky.

  • E: Equilibristic estimate, based on success being 50% likely, for critical chain planning.

ROPE example of a new task

When our team gets a new task, then the teammates who are likely to be doing the work get together to estimate.

If a task is large, such involving multiple teammates, stakeholders, user stories, use cases, or organizations, then we do a Work Breakdown Structure (WBS) that splits the task into smaller tasks.

If a task is simple, clear, and well understood, then we do a realistic estimate, and stop there.

If a task is complex, unclear, or less understood, then we do an optimistic estimate and pessimistic estimate. We aim for estimates that we can do as commitments to management and customers, such as ballpark 95% certainty. We also write a RAID log, i.e. we write down any risks, assumptions, issues, dependencies.

If a task is very complex, or new territory, or needs significant new knowledge to be understood, then we do an equilibristic estimate, and put it into our critical chain project management process. We also write a RAID log. We also aim for further WBS for these, including creating seperate research tasks, or development spikes, or stakeholder interviews, or customer research, etc.

ROPE stakeholders

ROPE estimates are the most successful way we're doing project management planning.

In our experience, ROPE is the best way to work across multiple organizations and multiple stakeholder perspectives.

  • R: Realistic works well for most stakeholders, and is what most people are already doing.

  • O: Optimistic works well with business leaders, who want to inspire, sell, market, or present.

  • P: Pessimistic works well with risk managers, who want to insure, budget, cap, or commit.

  • E: Equilibristic works well with project managers who target the best critical chain capabilities.

ROPE tooling

ROPE estimates work well with many kinds of project management tooling.

  • We use the Realistic estimate in typical project management tools, such as Jira, Trello, Asana, Basecamp, Project, etc.

  • We use the Optimistic estimate and Pessimistic estimate in project management tools that provide range estimates, or that enable us to add custom fields. We use these estimates to highlight ranges, such as during management meetings, to advise leadership of any opportunities for faster success, and of any risks for slower success.

  • We use the Equilibristic estimate in critical chain scheduling tools, such as Aurora, Exepron, LYNX, etc. Critical chain is the best project management scheduling solution that we've found. However, in our experience, many mainstream project management tools do not yet support critical chain scheduling, and many project managers are not as familiar with the technique.


Why use ROPE instead of any other way?

ROPE starts with the realistic estimate, which is quick and easy.

ROPE then adds the optimistic estimate. This proves useful in practice with stakeholders who are eager.

ROPE then adds the pessimistic estimate. This proves useful in practice with stakeholders who are cautious.

The equilibristic estimate is the most important estimate for wokring with project managers using critical chain. We believe critical chain scheduling is the best way forward for sophisticated projects and for agile/lean management.

We believe the ROPE mnemonic and the wording works well in practice because the wording focus on intent and feelings, rather than on exact precision.

What units does ROPE use?

ROPE can use any units.

Some estimates work well with units of time, such as hours Some estimates work well with units of cost, such as dollars. Some estimates work well with time and cost.

We work with some teams that use team-specific units, such as story points, or small/large sizes, or sprint cycles, or iteration loops, or budget tokens, or squad assignments, etc. In our experience, these can work well when the team creates shared understanding among stakeholders.

When we work with multiple organization, we always estimate using shared understanding, which typically means units of time in hours, and units of cost in U.S. dollars.

Does ROPE do minimum estimate and maximum estimate?

ROPE does not do a minimum estimate or maximum estimate.

We do have some clients who ask for these, such as for creating budget requests, or project plan ceilings, or not-to-exceed work rates.

For these clients, we can add these later if necessary.

In our experience, ROPE is a better agile estimation process than minimum-maximum estimation, and ROPE is also better way of working.