Story Points vs. Ideal Days: Which Agile Estimation Technique?

Story Points and Ideal Days are two popular Agile estimation techniques. Here's a quick comparison:

Feature	Story Points	Ideal Days
Measure	Relative effort	Time-based estimate
Best for	Comparing tasks	Easy understanding
Team experience	Experienced teams	New teams
Project type	Complex, changing tasks	Clear, well-defined tasks
Stakeholder preference	Open to new methods	Time-based estimates

Key points:

Story Points compare tasks without using time
Ideal Days estimate perfect workdays
Choice depends on team experience, project type, and stakeholder needs
Both methods have pros and cons
Teams can combine or switch methods as needed

Pick the method that fits your team and project best. Be ready to adapt if needed.

What are Story Points?

Story Points are a way Agile teams measure how much work a task needs. They help teams compare different tasks and plan their work better.

Definition of Story Points

A Story Point is a number given to a task. It shows how hard or big the task is compared to other tasks. It's not about time, but about how much effort the task needs.

How to Use Story Points

To use Story Points well, teams work together to figure out the number. They:

Talk about the task
Break it into smaller parts
Guess how much work each part needs
Give the whole task a number based on its size

Many teams use a game called Planning Poker to decide on Story Points. Here's how it works:

Step	Action
1	Each team member gets cards with numbers
2	Everyone picks a card to show how big they think the task is
3	The team talks about why they picked their numbers
4	They agree on a final number for the task

This way of working helps the team think hard about each task and work together to make good guesses.

What are Ideal Days?

Ideal Days are a way Agile teams measure how much work a task needs. They help teams plan their work better.

Definition of Ideal Days

An Ideal Day shows how long a task would take if nothing got in the way. It's about how much work a task needs, not how many days it takes in real life.

How to Use Ideal Days

To use Ideal Days well, teams should:

Pick a task
Break it into smaller parts
Guess how many Ideal Days each part needs
Add up the Ideal Days for the whole task

Step	Action
1	Pick a task
2	Break it into smaller parts
3	Guess Ideal Days for each part
4	Add up Ideal Days for the whole task

Ideal Days can be good for:

Helping everyone understand how big a task is
Planning work better
Setting good deadlines

Some teams like Ideal Days more than Story Points because they're easier to understand. But remember, Ideal Days aren't the same as real days. They're just about how much work a task needs.

Story Points vs. Ideal Days

Main Differences

Story Points and Ideal Days are two ways Agile teams guess how much work a task needs. They work differently:

Story Points: Compare tasks to each other, don't use time
Ideal Days: Guess how many days a task would take if nothing got in the way

Teams use Story Points with velocity to plan work. Ideal Days focus on time, but not real calendar days.

Pros and Cons

Here's how Story Points and Ideal Days compare:

Feature	Story Points	Ideal Days
Good things	- Compare tasks easily - Help team work together - Fast to use - Less pressure	- Easy to understand - Makes sense to people outside the team
Not so good things	- Hard to explain - First guesses might be wrong	- People aren't good at guessing time - Doesn't count problems that slow work - Might miss deadlines

When picking which way to use, think about:

What the team knows
What kind of project it is
What other people need to know

Knowing what's good and bad about each way helps teams pick the best one for their project.

Choosing an Estimation Technique

When picking between Story Points and Ideal Days for Agile estimation, teams need to think about a few key things.

Team Experience

How much the team knows about Agile matters:

Experience Level	Best Technique
New to Agile	Ideal Days
Experienced	Story Points

New teams often find Ideal Days easier to understand. Teams that know Agile well might like Story Points better because they're more flexible.

Project Type

The kind of project affects which method works best:

Project Type	Best Technique
Clear, well-defined tasks	Ideal Days
Complex, changing tasks	Story Points

Ideal Days work well for simple projects. Story Points are better for tricky projects where things might change.

What Stakeholders Want

What the people in charge want also matters:

Stakeholder Preference	Best Technique
Like time-based estimates	Ideal Days
Open to new Agile methods	Story Points

If bosses want to see time estimates, Ideal Days might be better. If they're okay with new ways of working, Story Points could be a good choice.

The main thing is to pick what works best for the team and the people they work with, not just what they're used to.

Using Story Points

Here's how to use Story Points well and what to watch out for:

Tips for Success

To use Story Points well, teams should:

Tip	Description
Use planning poker	Each team member guesses the Story Points for a task alone, then the team talks and agrees on a final number. This helps everyone understand the task.
Set a starting point	Pick a task you know well and give it a Story Point number. Use this to help guess other tasks.
Compare tasks	Think about how hard tasks are compared to each other, not how long they take. This helps keep guesses the same.
Get everyone involved	Ask all team members to help guess. This helps everyone understand the tasks.

Common Mistakes

Things to avoid when using Story Points:

Mistake	Why It's Bad
Changing guesses during work	This can mess up how fast the team works and cause problems.
Not thinking about how hard or risky tasks are	This can lead to bad guesses and poor choices about what to do first.
Listening only to the expert	Team members might just agree with the person who knows the most, leading to wrong guesses.
Not talking about wrong guesses later	If the team doesn't talk about mistakes, they might keep making them.

Using Ideal Days

Ideal Days is another way Agile teams guess how much work a task needs. It looks at how many days a task would take if nothing got in the way. Here's how to use Ideal Days well and what to watch out for.

Tips for Success

To use Ideal Days well, teams should:

Tip	What to Do
Explain Ideal Days clearly	Make sure everyone knows what Ideal Days mean and how they're different from real days
Guess tasks alone	Each team member should guess on their own to avoid copying others
Use the same way to guess	Pick one way to guess Ideal Days and stick to it
Think about how hard tasks are	Remember that some tasks are harder than others when guessing
Check and fix guesses	Look at how long tasks really took and change your guesses to get better

Common Mistakes

Things to avoid when using Ideal Days:

Mistake	Why It's Bad
Mixing up Ideal Days with real days	Ideal Days are about work time, not calendar days
Not thinking about how hard tasks are	Forgetting that some tasks are trickier can lead to bad guesses
Forgetting about breaks and problems	Ideal Days don't count things that slow work down
Not looking at old guesses	If you don't check your old guesses, you won't get better at it

Combining Methods

Sometimes, teams might want to use both Story Points and Ideal Days together. This can help them get the good things from both ways of guessing how much work a task needs.

Using Both Techniques

Here are some ways teams can use both Story Points and Ideal Days:

Method	How It Works
Convert Ideal Days to Story Points	Use Ideal Days to guess how long a task takes, then change it to Story Points
Mix for different team members	New team members use Ideal Days, while others use Story Points

Using both ways can help teams:

Get better at guessing how long tasks take
Keep track of how fast they work
Plan their work better

When to Use a Mixed Approach

Here's when it might be good to use both Story Points and Ideal Days:

Situation	Why Use Both
Team has new and old members	Helps everyone understand the guesses
Project has easy and hard tasks	Can use the best way for each kind of task
Bosses want different kinds of info	Can give time guesses and show how fast the team works

When deciding to use both ways, think about:

How much the team knows about Agile
What kind of project it is
What the bosses want to know

Using both Story Points and Ideal Days can help teams guess better and make everyone happy with the information they get.

Effects on Teams and Projects

Team Collaboration

Story Points and Ideal Days affect how teams work together in different ways:

Method	Effect on Team Collaboration
Story Points	- Helps team members work together - Encourages talking and understanding - Makes the team closer
Ideal Days	- Can make team members work alone - Might reduce talking between team members - Can lead to less teamwork

Sprint Planning and Velocity

Both ways of guessing work affect how teams plan sprints and track speed:

Aspect	Story Points	Ideal Days
Tracking Speed	Easy to track how much work is done	Harder to track how much work is done
Planning Sprints	Can be less accurate for time	Can help plan time better
Estimating Future Work	Good for guessing future work	Less helpful for guessing future work

Teams should pick the method that works best for how they like to work together and plan their projects.

Changing Estimation Methods

How Practices Change Over Time

As teams get better at Agile, they often change how they guess work size. This can happen because:

Projects change
New people join the team
Teams try new ways of working

For example, a team might start with Ideal Days but later switch to Story Points. This can help them work better together and track their progress.

Teams might also mix different ways of guessing to find what works best for them.

Signs to Change Methods

How do you know when to change your guessing method? Look for these signs:

Sign	What It Means
Work speed keeps changing	Your guesses might not show how much work the team can do
Team members don't join in	The current way might not help people work together
Guesses are often wrong	This can cause delays or too much work

If you see these signs, it might be time to try a new way of guessing work size.

Conclusion

Key Takeaways

Picking between Story Points and Ideal Days for Agile guessing depends on:

How much the team knows
What kind of project it is
What the bosses want

Both ways have good and bad points. Teams should think about these when choosing.

Story Points:

Don't use time
Help teams work together
Make it easy to see how fast work gets done

Ideal Days:

Use time to guess
Are easier to explain to bosses
Can be harder to use for big projects

The best way is the one that works for the team and project. It's good to be ready to change if needed.

Choosing the Right Method

Here's what to think about when picking Story Points or Ideal Days:

Factor	Story Points	Ideal Days
New team	Harder to use	Easier to start with
Old team	Good for experienced teams	Might be too simple
Clear project	Might be too vague	Works well
Tricky project	Helps deal with changes	Might not work as well
Bosses want time info	Hard to explain	Easy to understand
Bosses care about speed	Shows team speed well	Doesn't show speed as well

Pick the way that fits your team and project best. It's okay to try both and see what works.

FAQs

What are the advantages of estimating in ideal days comparing to story points?

Ideal days have two main benefits over story points:

Advantage	Description
Easier to explain	Stakeholders can understand them better as they're like regular time estimates
Faster to estimate	Teams can make guesses more quickly without needing to be as exact as with story points

How do story points compare to ideal days?

Aspect	Story Points	Ideal Days
Accuracy	More accurate for timelines and tracking	Less accurate but still useful
Best for	Experienced Agile teams	Teams new to Agile estimation
Choice depends on	Team experience, project type, what stakeholders need	Same factors as story points

What is ideal days in Agile estimation?

Agile

Ideal days show how long a team would take to finish a project if:

They only worked on that project
They had no interruptions

This means ideal days assume a perfect work setting with:

No distractions
No obstacles

Teams can focus only on the task at hand in this imaginary situation.

Story Points vs. Ideal Days: Which Agile Estimation Technique?