TFB / NFC / S

Esta página es una versión traducida de la página TFB / NFC / S. La traducción está completa al 100 %.

⏱ 3 min · 📅 2026

TFB / NFC / S is a lightweight estimation and classification technique that groups work items into coarse categories: trivial, easy but not trivial, non-functional or not classified, and small but not trivial. It is used to quickly sort tasks or backlog items when fine-grained estimation is not needed.

It can be considered close to Large /Uncertain/ Small and to bucket-based classification techniques such as Bucket System, although with more specific categories for quick conversations.

Like any estimation technique, it should be used with the team's context, the type of work, and the purpose of the estimation in mind. It does not fit every case, nor does it automatically replace other, more granular techniques.

What it is for

Quickly ordering tasks or backlog items;
Reducing the time spent on detailed estimates;
Separating obvious work from uncertain work;
Detecting items that need refinement;
Helping small teams with comparable tasks;
Starting a sizing conversation without getting into story points yet;
Grouping items before using another estimation technique.

Its greatest value lies in initial classification, not in exact capacity planning.

How to apply it

Identify the tasks or items. The team gathers the items it wants to classify.
Agree on the meaning of each category. Before estimating, the team should share what it understands by trivial, easy, unclassified, or small.
Classify initially. Each item is assigned to a category.
Discuss the doubtful cases. If a task is not obvious, the team talks it through to understand its size or uncertainty.
Refine what is unclassified. NFC items require more information, splitting, or research.
Decide the next step. The team may select, split, postpone, or re-estimate using another technique.
Assign numerical sizes only if it adds value. It is not mandatory to convert the categories into numbers.

Example

Item	Possible category	Reason
Fix a typo on a screen.	T	Obvious and very small work.
Add a simple field to an existing form.	FB	It doesn't seem difficult, but it requires implementation, review, and testing.
Integrate an unfamiliar external API.	NFC	Not enough technical information to classify it.
Add a business validation to a known flow.	S	It's small, but not trivial: it affects rules and tests.

The category should not be taken as objective truth. It is an aid to conversation.

NFC does not mean "unimportant"

A common misconception is to treat NFC as a low-priority category. It is not.

NFC indicates that the team cannot yet classify the item with sufficient certainty. This may be due to a lack of information, a technical dependency, functional ambiguity, or a need for research.

An NFC item may turn out to be small, large, urgent, or disposable. Before deciding, it needs refinement.

Relationship with refinement

TFB / NFC / S can be used during Product Backlog refinement to separate clear items from items that need more conversation.

For example:

T or FB items can move forward with little discussion;
S items may need acceptance criteria or splitting;
NFC items should go back to discovery, technical analysis, a spike, or a conversation with the Product Owner.

The goal is to avoid spending the same refinement effort on every item.

Relationship with Sprint Planning

This technique may be too coarse to determine exact sprint capacity. In Scrum, planning is not just about adding items until a box is full: the team selects work to achieve a Sprint Goal.

TFB / NFC / S can help detect whether an item is too unclear or seems manageable, but for planning it may be necessary to complement it with conversation, story splitting, acceptance criteria, and an assessment of actual capacity.

Comparison with other techniques

Technique	Level of detail	Main use
TFB / NFC / S	Low.	Quick classification of tasks or items.
Large / Uncertain / Small	Low.	Separating manageable, large, or uncertain items.
T-shirt sizing	Medium.	Estimating relative size with an intuitive scale.
Planning poker	Medium or high.	Estimating stories through team consensus.
Bucket System	Medium.	Quickly classifying many items into size groups.

There is no universally best technique. The technique should be chosen based on the cost of estimating, the need for precision, and the level of uncertainty.

TFB / NFC / S and AI

AI can help prepare an initial classification of tasks, detect ambiguities, or suggest items that should be marked as NFC.

But it should not make the estimation decision on the team's behalf. In work involving generative AI, there is also a trap to avoid: classifying a task as trivial just because the agent can quickly generate a first output.

Generation may be fast, but review, integration, and validation still count as work.

Good practices

Use the technique for quick classification, not for false precision.
Agree within the team on what each category means.
Treat NFC as a signal of uncertainty, not as a discard bin.
Split or investigate items that are too unclear.
Complement it with other techniques if finer-grained planning is needed.
Review estimates when new information emerges.
Do not compare categories across different teams as if they were objective measures.

Limitations

It does not calculate exact capacity;
It does not measure productivity;
It does not replace refinement;
It may be too coarse for Sprint Planning;
It depends heavily on the team's judgement;
It may hide significant differences between tasks classified the same way;
It can create a false sense of security if NFC items are not reviewed.

Common mistake

Using it as a fine-grained sprint estimation. TFB / NFC / S is useful for quickly ordering and classifying work, but its categories are too coarse to always replace a planning conversation. Especially in Scrum, the team must check whether the selected work allows it to achieve the Sprint Goal without overcommitting.

Resources

📄 Scrum Master v.4.0Free download · Scrum Manager

Category	Meaning	Typical use
T	Trivial.	Very simple, obvious, low-effort work.
FB	Easy but not trivial.	Clear work without great difficulty, but requiring some dedication.
NFC	Non-functional or not classified.	Work that cannot be classified yet or that requires clarification.
S	Small but not trivial.	Relatively small work, but with enough effort or attention involved that it should not be treated as trivial.