HF Design for Operability and Maintenability Dipl.-Ing. Simon G. Kariuki & Dr.-Ing. Katharina Löwe Technical University of Berlin Presented at The PRISM

HF Design for Operability and Maintenability

Dipl.-Ing. Simon G. Kariuki &

Dr.-Ing. Katharina Löwe Technical University of Berlin

Presented at The PRISM Seminar, FG2

Athens, 3rd & 4th Sept, 2003

Technische Universität Berlin

What is covered:


Background, why the need for HF in design.

HF Models for design, inspection and maintenance.

Examples where design ignored HF.


Why Human Factor?

Time

Sa

fety

Imp

rov

eme

nt

Engineering/ Hardware

age

(Upto 1970s)

Safety Management Systems

age

(Upto mid-1980s)

Industrial Revolution 2003

Human Factors Age

(Current)


Design

Output

The Design Team

Human Factors Experts

-Ergonomists

-Psychologists

Designers

-Engineers

-Chemists

Operator (User)

-Process Operators

-Maintenance Technicians

Man

agem

ent


Participatory design that involves operator (as the user) participation and task modelling at early stages.

To make all departments feel that they own the design process.

Human Factors are included from early stages and not to only for cosmetic purposes.

The Principle

To train Engineers to be HF experts

To involve cognitive and physical ergonomists permanently & actively in design projects


Manage-ment

Systems

Human(User)

Plant(Machine)

Design

Operator (active errors)

Task performanceTraining,Communication

Equipment reliability

HF

BA

RR

IER

Design and Management (latent errors)

Minimise consequences

HF Design Guidelines

Design solution to address error causesError causes

Undesired Event

Local triggerLocal trigger

OR

Minimise error occurence


Conceptual Design

Basic Desig

n

Commissioning &

Installation

Check

Evaluate

Review

Detailed

Design

HF Iterative design Model


Conceptual Design

Basic Desig

n

Abstract of design

HF reviews

Overview of tasks

Commissioning &

Installation

Check

Evaluate

Review

Detailed

Design



Conceptual Design

Basic Desig

n

Abstract of design

HF reviews

Overview of tasks

User profile: Biometrics

Task analysis

•Critical tasks, Task scenarios

•Subtasks formulation

Function analysis

Link analysis

Commissioning &

Installation

Check

Evaluate

Review

Detailed

Design



Conceptual Design

Basic Desig

n

Abstract of design

HF reviews

Overview of tasks


Task analysis



Function analysis

Link analysis

Commissioning &

Installation

HF training for contractors

Feedback for an improvement

Check

Evaluate

Review

Detailed

Design



Conceptual Design

Basic Desig

n

Abstract of design

HF reviews

Overview of tasks


Task analysis



Function analysis

Link analysis

Commissioning &

Installation

HF training for contractors

Feedback for an improvement

Check

Evaluate

Review

Detailed

Design



Detailed presentation of design

Application of HF guidelines

Task analysis review

Detailed design

Check Evaluate

Review





Simulation

Prototyping

Operator testing & training

Cognitive walkthroughs

Detailed design

Check Evaluate

Review





Simulation

Prototyping



Specifications

Error causes & precursor Analysis and mitigation

Evaluate results

New concepts needed?

Detailed design

Check Evaluate

Review





Simulation

Prototyping



Specifications

Error causes & precursor Analysis and mitigation

Evaluate results

New concepts needed?

Are the error causes & precursors designed out?

Are they guarded against?

Warn against?

Training to avoid error occurrence?

Detailed design

Check Evaluate

Review

Designing to reduce

Human Error Precursors

= HF Guidelines

Work Environment

Ventilation, Air Conditioning

Noise reduction

Lighting and Glaring

Work space layout

Maintainability and Operability

Accessibility issues

Process Equipment

Line Valves & Relief Valves

Pipes, hoses and connectors

Fasteners, gaskets and seals

Automation

Fault Management

False Alarms

Training

Process Control & Monitoring

Control Room Design

Field Control Panels

Alarm Management

Control Panel Design

Display Design


Process Operations & Layout

Process (Equipment) Layout

Pathways design

HF Main Areas

Analysis of accidents

13%

18%

25%14%

30%

Normal process

Loading/unloading

Maintenance/repair

Startup/shutdownoperation

Others:

50%

28%

7%

15%

Normal process

Maintenance/repair

Startup/shutdownoperation

Others

Uth, 1999

TUB Internet Survey


Fatality due to maintenance accidents

Breakdow n &Scheduledmaintenance(66%)

Cleaning (25%)

Inspection,lubrication,painting (9%)

Lees, 1996


Initiate

Access

Search

Decision &

Response

Action Example

HF Design Requirement

Steps

Inspection ModelTechnische Universität Berlin

Initiate Access Searc

h

Decision &

Response Read &

understand work card

Select inspection tools.

Calibrate if necessary (NDI equipment)

Work card design

Permit –to-work procedures

Action Example


Steps


Initiate

Access Search

Decision &

Response Read &




Locate area on the plant

Move to work site

Work card design


Proper & clear labelling.

Avoid difficult-to-reach areas.

Easy & safe isolation.

Purging

Action Example


Steps


Initiate

Access

Search

Decision &

Response Read &





Move to work site

Move eyes or probe on search areas

Work card design





Purging

Clear accessroutes.

Good lighting

Reachable locations

Action Example


Steps


Initiate

Access

Search

Decision &

Response Read &




Re-examine area of indication and mark as a defect if necessary.

Write a Non routine repair (NRR)


Move to work site

Move eyes or probe on search areas

Work card design





Purging

Clear accessroutes.

Good lighting

Reachable locations

Training of maintenance personnel.

Action Example


Steps


Initiate

Site Access

Part Access Buy-

backSteps

Repair/Maintenance Model

Reset

HF

Des

ign

Req

uire

men

tA

ctio

n Ex

ampl

e


Initiate

Site Acces

s

Part Access Buy-

back

Make tools ready, collect parts, inspect parts Well design parts stores with parts clearly, logically labelled & numbered

Steps


Reset

HF

Des

ign

Req

uire

men

tA

ctio

n Ex

ampl

e


Initiate

Site Acces

s

Part Access Buy-

back

Make tools ready, collect parts, inspect parts

With tools, parts, equipment

Isolate equipment/ plant

Well design parts stores with parts clearly, logically labelled & numbered

Sufficient pathways to worksite with all required tools & equipment included

Easy & Safe Isolation

Steps


Reset

HF

Des

ign

Req

uire

men

tA

ctio

n Ex

ampl

e


Initiate

Site Acces

s

Part Access Buy-

back



Isolate equipment/plant

Isolate equipment.

Open the parts that need repair




Accessibility of part. to avoid working at awkward positions

Easy &safe isolation

Purging

Steps


Reset

HF

Des

ign

Req

uire

men

tA

ctio

n Ex

ampl

e


Initiate

Site Acces

s

Part Access Buy-

back




Isolate equipment.







Purging

Steps


Reset

Adjust systems to specs and inspect adjustment.

Gauges and other indicators easily readable and shall be within eye reach

HF

Des

ign

Req

uire

men

tA

ctio

n Ex

ampl

e


Initiate

Site Access

Part Access Buy-

back


Examine if repair meets standards.

Close & document



Isolate equipment.







Purging

Training of maintenance personnel.

Good communication

Steps


Reset

Adjust systems to specs and inspect adjustment.

Gauges and other indicators easily readable and shall be within eye reach

HF

Des

ign

Req

uire

men

tA

ctio

n Ex

ampl

e


Repair/Maintenance Example

Pasadena Incident, October 23rd 1989

Loop reactor Schematic

Product Take Off Valve


Settling leg



Typical Piping Settling Leg arrangement

Settling leg of a reactor:

General Piping

Settling legs clogged by plastic material.

Frequent cleaning was needed.

The clogged leg is isolated but reactor keep on operating.




DEMCOR Valve

Valve operated by air.

Connectors for „open“ and „close“ were identical.




Consequences

Explosion with the force of 2.4 tons of TNT

23 fatalities

More than 130 injuries

Nearly a billion dollars in asset damaged

HF design questions Was the isolation easy and safe?

Was the alarm system detectable, could it be discriminated?

Were the access/escape routes designed to contain an emergency situation, were they clearly marked?


Tank 1

Tank 2

Tank 3

Valve 1

Valve 2

Valve 3

From loading rack

Product1

Product3

Product2

Task

•To fill tank 1:

Close Valves 2 & 3 and open valve 1.

Possible error:

Either valve 1 or 2 or both valves are left open

Product to the wrong tank

Task

•To fill tank 1:

Close Valves 2 & 3 and open valve 1.

Possible error:

Either valve 1 or 2 or both valves are left open

Product to the wrong tank

Operational example Technische Universität Berlin

Solution

Each tank to be connected to

filling point by an independent pipe

1. Each filling pipe to have a

different size or a special coupling

2. Work space big enough accomodate operators hands with PPE

3. Filling point lifted to avoid too much bending


Conclusions Technische Universität Berlin

HF should be as old as the conceptual stage of a design process.

Iterative design process helps to reduce error causes

before the whole design process is concluded.

The Primary function of a design engineer is to make things difficult for the fabricator and

impossible for the the serviceman.

Most important is to eliminate the Myth:

Thank you for your kind attention


Documents

HF Design for Operability and Maintenability Dipl.-Ing. Simon G. Kariuki & Dr.-Ing. Katharina Löwe Technical University of Berlin Presented at The PRISM