Root cause analysis · 5 Whys + 8D report No service

The promise that never reached the network

She was told her calls would work abroad. They did not. Here is why, and how to prevent it.

Presented byDimas Davila
Presented toLucas Ticiani · Juliana Cuesta
Date15 October 2026
Mrs. Susan, just landed.
AgendaAbout 25 minutes

From one complaint to a process that keeps its promises

01

The case

What happened to the customer, and where the process broke.

5 min
02

Root cause

Appendix A. Finding the root cause with the 5 Whys.

5 min
03

8D report

Appendix B. The corrective action report, from D1 to D8.

12 min
04

Wrap-up

The standards behind it, and what this means for the role.

5 min
Dimas Davila
01

The case

A work trip, a call made on time, and a promise that did not hold.

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The caseSource: Appendix A

She asked on time. She got a yes. It still failed.

A week before

She calls

She asks her provider to lift international calling restrictions.

Same call

“Yes”

The provider confirms they will be lifted on her departure date.

Arrival

No calls

She cannot make calls and has to find another phone.

Hours later

Slow fix

She cannot validate some account data. Several departments get involved.

After

Complaint

She asks for compensation and the provider refuses.

1 · Service failure

They confirmed the restrictions would be lifted on her departure date. They were not.

2 · Recovery failure

Calling from another phone, she could not validate her data. She was passed between departments and the fix took hours.

3 · Customer care failure

She asked for compensation and was refused, so it became a formal complaint.

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The customer did everything right. The company should have found the failure. She found it first.

…in another country, with no phone.

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The caseEvidence first

What we know, and what we must check

Facts

Appendix A

International calling restrictions can be lifted on request, but the provider may require a deposit or spending limit on the account.

Appendix A

When a provider promises something to a customer, the customer expects it to be delivered.

The complaint

The change was confirmed for her departure date. Restoring the service took hours and involved several departments.

Assumptions · verified in D4

A1

A deposit or spending limit was needed, and its approval was never completed.

A2

The agent could confirm without a system check, and the “yes” had no owner or follow-up.

A3

When the scheduled change failed, nobody got an alert and the customer got no message.

ISO 10002Complaints handling principle: objectivity. Decisions are based on facts, not opinions.

Dimas Davila
The caseProcess map

Follow the request from the call to the network

Customer call

She asks to lift the restrictions for her trip.

Fact

Agent says yes

The agent confirms it for her departure date.

Fact

Credit approval

A deposit or limit needs approval, but nobody approves it.

A1

Follow-up task

The “yes” has no owner or follow-up, so the change does not run on her date.

A2

Check and notify

Nobody is alerted, and she gets no message.

A3

Customer abroad

She lands and finds she cannot call.

Fact

Two breaks: the “yes” came too early, and nobody checked the result

Red steps are assumptions A1 to A3, verified in D4
02

Root cause

Appendix A. The 5 Whys, twice: why it happened, and why nobody saw it.

Dimas Davila
Root causeTechnique

Why I chose the 5 Whys

  • The failure is a chain of steps: one step failed, so the next one failed too.
  • It finds the cause in the process, not a person to blame.
  • Each answer can be checked with records, such as system logs or call recordings.
Round 1 · occurrence

Why did the restriction stay active?

Root causeNo system control for future-dated changes
Round 2 · escape

Why did nobody notice before she landed?

Root causeNo closed loop after the promise
Problem statement

A change confirmed for her departure date was not made, and she only found out when she landed abroad.

Why not a fishbone?

A fishbone is best when many causes act together (people, method, machine, material). Here there is just one chain of events, so the 5 Whys fits better.

ISO 9001 · 10.2Find the causes before choosing actions.

Technique chosen: 5 Whys
Root cause · round 1Why did it happen?

The “yes” came before the system could deliver it

?
No calls on arrival, even though the change was confirmed.
1
The international calling restriction was still active on her line.Check: account status log
2
The scheduled change to lift it did not run.Check: system job history
3
The required deposit or spending limit approval was not completed.Check: credit record · A1
4
The system let the agent confirm the change without checking that approval.Check: CRM and call recording · A2
5
Root cause: there is no standard, system-controlled process for changes scheduled for a future date.

Failure 1: the service

It is not just “the agent made a mistake”.

The system allowed it, so any agent could make the same mistake.

Why 3 to 5 are hypotheses until D4 verifies them
Root cause · round 2Why did nobody see it?

Nobody checked that the promise was delivered

?
The customer found the failure abroad. The company did not.
1
Nobody checked that the change ran on her departure date.
2
She got no message confirming that the service was active.
3
When a scheduled change fails, the system sends no alert.
4
No person or team is responsible for failed changes.
5
Root cause: there is no closed loop. Success is measured when the call ends, not when the promise is delivered.

Failures 2 and 3: recovery and customer care

Identity check

Calling from another phone, she could not validate her account data.

No single owner

Her case was passed between several departments.

Compensation

It was refused, even though the company broke its promise.

Why 1 to 4 are hypotheses (A3) until D4 verifies them
03

The 8D report

Appendix B. Eight steps, from protecting the customer to closing with proof.

D1Team
D2Problem
D3Contain
D4Root cause
D5Choose
D6Validate
D7Prevent
D8Close

Doing an action is not enough. It is closed only when the data shows it works.

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D1 · The team
D1D2D3D4D5D6D7D8

One person from every step of the process

RoleAreaWhy
SponsorCustomer service managerOwns the complaint and approves compensation
8D leaderQualityRuns the 8D method and keeps the evidence
MemberCustomer careKnows how agents confirm requests (step 2)
MemberCreditApproves deposits and spending limits (step 3)
MemberIT systemsRuns scheduled changes and alerts (steps 4–5)
MemberSecurityDefines how customers verify their identity
D0 · Before we start: does this case need a full 8D?

Yes, because the severity is high: the customer was left without service abroad, the company broke a promise, and it ended in a formal complaint.

Process steps (slide 7) · who covers each
  1. 1Customer callCustomer care
  2. 2Agent says yesCustomer care
  3. 3Credit approvalCredit
  4. 4Follow-up taskIT systems
  5. 5Check and notifyIT systems
  6. 6Customer abroadSecurity
Proposed team · short daily meeting during containment, weekly review until closure
D2 · The problem
D1D2D3D4D5D6D7D8

Describe the problem with data, not guesses

What
The international restriction was not lifted, although it was confirmed.
Who
Mrs. Susan, traveling for work.
Where
At her destination, when she landed.
When
Requested a week before the trip, to start on her departure date.
Why it matters
A broken promise that ended in a formal complaint.
How found
By the customer, not by the company.
How many
One known case. She had no calls for several hours.

To find out

Scale

How many other scheduled changes have failed in the same way?

Is / is not

Do changes made immediately, during the call, also fail?

A change confirmed for her departure date was not made, and she only found out when she landed abroad.

Tool: 5W2H · ISO 10002: investigate with facts
D3 · Containment
D1D2D3D4D5D6D7D8

Protect her first, then every customer at risk

#Temporary actionOwnerWhen
For her
3.1Confirm her line works now and apologize personallyCareToday
3.2One contact person until the case closes, and a fair compensation offerSponsor24 h
For every customer at risk
3.3Find every pending international change with an open approvalIT + Credit24 h
3.4Call those customers and fix it before they travelCredit + Care48 h
3.5Until D6: activate the service during the call, never as a scheduled changeCareFrom today

This stops the damage, but it does not fix the cause.

ISO 9001 · 10.2React to the problem: control it, correct it and deal with the consequences.

Times are my proposal
D4 · Root cause
D1D2D3D4D5D6D7D8

Two root causes to verify before we act

Why it happened

There is no system control for future-dated changes, so an agent can say “yes” before the approval is done.

Why nobody saw it

There is no closed loop: a failed change sends no alert, and the customer gets no confirmation.

How I verify them

1 · Records

Compare her call recording, CRM notes, credit record and system logs with the 5 Whys.

2 · Repeat it

Schedule a change on a test account with a pending approval. Does it fail the same way?

3 · Size

Review past scheduled changes. How many failed, and how many customers were never told?

ISO 9001 · 10.2Find the causes, and check whether similar cases exist.

If the data does not match, go back to the 5 Whys
D5 · Permanent actions
D1D2D3D4D5D6D7D8

Fix the system, not only the people

OptionFixesEffectDecision
A · Only train the agents (it depends on memory)1 · ServiceLowNot alone
B · System check: the agent cannot confirm until the deposit or limit is approved1 · ServiceHighSelected
C · Closed loop: if the change fails, someone is alerted. If it works, the customer gets an SMS1 · ServiceHighSelected
D · Traveler support: one owner per case, and another way to verify identity from abroad2 · RecoveryMediumSelected
E · Fair compensation: automatic credit when the company breaks a promise3 · Customer careMediumSelected

ISO 9001 · 8.2.3Option B puts this clause into the system: confirm we can deliver before we promise.

Effect is my estimate
D6 · Implement and validate
D1D2D3D4D5D6D7D8

Verify it works, then prove it fixed the problem

Verification · did we build it right?

ActionTestPass if
BSystem checkConfirm a change while the deposit is still pendingThe system blocks the “yes” and shows what is missing
CClosed loopForce a scheduled change to fail on a test accountThe owner gets an alert and no “active” SMS is sent
CClosed loopRun a scheduled change that worksThe customer gets the confirmation SMS
DTraveler supportVerify identity with a code by email, from a foreign numberThe agent can verify and restore service
EFair compensationSimulate a failure caused by the companyThe credit is proposed automatically

Validation · did it fix the problem?

Baseline (D4 data) Pilot · one area Rollout · all areas Changes done on the promised date Weeks Control limits Target agreed with the sponsor Go / no-go Remove D3 rules

Illustrative chart: it shows how results will be read, not real data.

Changes on the promised dateCustomers notifiedTime to restore abroadRepeat complaints
ISO 9001 · 10.2: review the effectiveness of corrective actions
D7 · Prevention
D1D2D3D4D5D6D7D8

Make the fix the standard, and look for the same risk

my favorite step

Standardize

  • Write a procedure for future-dated changes
  • Update the agents' call script
  • Train care, credit and IT staff

Apply elsewhere

  • Apply the same check to other scheduled changes, like plan changes
  • Add this failure mode to the process

Measure

  • Review complaints by cause every month
  • New : promises kept on time

Where else in the company can someone promise a result that no system is tracking?

ISO 10001Promises to customers should be clear and kept. ISO 9001 · 10.2Update the risks after a nonconformity.

Dimas Davila
D8 · Closure and recognition
D1D2D3D4D5D6D7D8

Close with proof, share lessons, thank the team

8D closure record

Case: international calling restriction not lifted

  • All D6 goals met over an agreed period
  • The customer was contacted and is satisfied
  • All actions closed, each one with evidence
  • Lessons shared with the teams involved
Sponsor sign-offApproved

Lessons learned

1

A promise to a customer is a requirement.It needs a system that tracks it until it is delivered.

2

Measure what the customer receives.Not only what we do, like the length of the call.

3

Each complaint shows a weak point.It is free information to improve the process.

Recognition: thank the team openly and share this 8D as a case study.

ISO 9001 · 10.2.2Keep evidence of causes, actions and results. ISO 10002Close the complaint and inform the customer.

Closed means it works and it lasts
Wrap-upSummary

The whole 8D on one page

Problem

A confirmed change was not made. She had no calls abroad for hours, and compensation was refused.

Root cause

Before the “yes”: no system check of the approval.

After the “yes”: no check that it was delivered.

Actions

System check, failure alerts, SMS to the customer, one case owner and fair compensation.

Target

Changes made on time, customers notified, and no repeat complaints.

Dimas Davila

The customer did everything right. The process let the company promise what it could not guarantee.

If you remember one thing, remember this.

Dimas Davila
Wrap-upStandards · 1 of 2

The standards behind this 8D

StandardWhat it saysWhere it applies here
Customer satisfaction guidelines (ISO 10000 family)
ISO 10002:2018Guidelines for complaints handlingA complaints process: receive, track, acknowledge, assess, investigate, respond, close. Principles include responsiveness, objectivity and accountability.Failures 2 and 3: slow response, no single owner, compensation refused. D3, D5 (D, E), D8.
ISO 10001:2018Guidelines for codes of conductHow an organization makes promises to its customers, and how it keeps them.The confirmed “yes” was a promise. D7: KPI on promises kept.
ISO 10004:2018Guidelines for monitoring and measuringHow to monitor and measure customer satisfaction.D7: monthly review of complaints by cause.
ISO 9001:2026 · Quality management systems, requirements
8.2.1Customer communicationCovers customer feedback, including complaints.D2: the complaint is the starting point of the analysis.
8.2.3Review of requirementsBefore committing to the customer, make sure the organization can meet the requirements.Root cause. D5 option B.
9.1.2Customer satisfactionMonitor whether customers feel their needs and expectations were met.D6: targets to measure the result.
10.2Nonconformity and corrective actionReact, find the causes, check for similar cases, act, review effectiveness, update risks, keep evidence.The whole 8D, D3 to D8.
ISO 9001 is a requirements standard. ISO 10001, 10002 and 10004 are guidelines
Wrap-upStandards · 2 of 2

The same principles in a Field Engineer's work

ISO/IEC 170652012 · Requirements for bodies certifying products, processes and services

Includes surveillance of certified products when the scheme requires it, and a process for complaints and appeals.

In the field: follow-up visits confirm the product still conforms.

ISO/IEC 170202026 · Requirements for bodies performing inspection

Impartiality, competent staff, defined methods, inspection records and reports.

In the field: each finding is recorded and based on evidence.

ISO/IEC 170252017 · Competence of testing and calibration laboratories

Valid results, traceable measurements, and a process for complaints.

In the field: measurements I take must be traceable.

ISO 190112026 · Guidelines for auditing management systems

Audit principles include integrity, independence and an evidence-based approach.

In the field: conclusions come from evidence, not opinion.

Same idea as this 8D: decide on evidence, stay impartial, and prove that the fix works.

Year = edition in force, October 2026
Wrap-upThe role

What I bring, and where you saw it today

Dimas DavilaFor the field team
For the field teamDimas Davila
What I stand by in the field
  1. A finding without evidence is just an opinion.Every nonconformity I raise rests on a record, a measurement or a photo.
  2. I report what I see, not what anyone wants to hear.Impartiality is what makes a certificate worth trusting.
  3. A fix is not closed until it is verified.The follow-up visit is where the 8D really ends.
01Structured problem solving5 Whys and 8D, from the symptom to the root cause.Seen todaySlides 9–20
02Evidence over opinionFacts and hypotheses kept apart, then verified.Seen todaySlides 6 · 16
03Standards literacyISO 9001, ISO 10002, ISO/IEC 17065 and 17020.Seen todaySlides 23–24
04Fix the system, not the personRoot causes in the process, prevention in other areas.Seen todaySlides 10 · 19
05Verification and validationTest plans and control charts to prove a fix works.Seen todaySlide 18
06Clear communicationSimple language for clients, in English and Spanish.Seen todayThis presentation
Dimas Davila
Thank you

Questions are welcome.

Dimas Davila

Dimas Davila
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