Author: MARA ĆUJIĆ

An Analysis of the Task List impact upon RAMS

Workload Calculations

November, 2004

CONTENTS√ Information about CEATS

√ Objectives

√ Research process and data collected

√ Setting scenarios for running RAMS

√ Sensitivity analysis

√ Comparison of workload results

√ Survey in national ACC

√ Conclusions and Recommendations

CEATS

♦ CSPDU

♦ CRDS♦ CUAC

♦ CTC

CRDS

√ FTS2, FTS3

√ SSRTS1, SSRTS2, SSRTS3, RTS1

It was done:

In progress:

√ FTS4, SSRTS4, RTS2

RTS i FTS

OBJECTIVES

PROBLEM OBJECTIVES

Questionnaire with controllers who had experience in RTS

1. Task list (FTS3)2. Task duration times3. Task distribution4. There was not task list for CEATS

1. New task list definition2. Estimation of task duration times3. New task distribution4. Unique task list for CEATS

DisagreementRTS and FTS

SURVEY

QUESTIONNAIRE (10 CEATS controllers + RTS expert )

1.Start questionnaire 2.Progress questionnaire 3.Final questionnaire♦ defining first new, ♦ new ideas for designing ♦ 31 tasks (29+2) were task list the final questionnaire included in task list ♦ ( 29 tasks) ♦ data for analysis

TASK LIST IN FTS3 (15) WAS TAKEN IN CONSIDERATION

INTERVIEW (10 CEATS controllers)

♦ IT WAS REALISED IN ORDER TO COMPLETE QUESTIONNAIRE RESULTS

Final Questionnaire

FIRST PART OF THE QUESTIONNAIRE

No. TASK NAME min (s) max (s) PC EC PC/EC

1 Check flight plan   1 2 3

2 Update flight plan   1 2 3

√ Information about minimum and maximum task duration times

√ Task distribution between controllers

3 54 7

SECOND PART OF THE QUESTIONNAIRE

No. TASK NAME

Very small Small Medium High Very high

importance importance importance importance importance

1 Check flight plan          

2 Update flight plan          X

X

√ Estimate the importance of the tasks

√ Busy sector and high workload were considered

√ Values from 1 to 5 were aligned to each task

Final Questionnaire

THIRD PART OF THE QUESTIONNAIRE

√ Estimate the frequency of task execution

√ Peak hour period was taken in consideration

No. TASK NAME

Very small Small Medium High Very high

frequency frequency frequency frequency frequency

1 Check flight plan          

2 Update flight plan          

X

X

√ Values from 1 to 5 were aligned to each task

Final Questionnaire

RESULTS

√ Average minimum and maximum values of task duration times

√ Average values for importance of each task

√ Average values for frequency of task execution

√ Task distribution between controllers

√ Factors affecting controller workload

THE TASK LISTTHE MOST IMPORTANT TASKS

1. Conflict resolution (4.91)

2. Pilot readback to instruction(4.82)

3. Surveillance of A/C in sector(4.73)

4. Level change coordination (4.73)

5. Monitoring of all A/C influenced by an A/C climbingor descending (4.64)

THE MOST FREQUENT TASKS

1. Pilot readback instruction (4.55)

2. Surveillance of A/C in sector (4.45)

3. Identification of A/C (4.36)

4. R/T handover to CEATS sector (4.18)

5. First call of A/C (4.18)

ACTORS

(31) TASKS

(1) TASK

(14) TASKS

(16) TASKS

PC

EC

PC/EC

Task distribution between controllers

Running RAMS1. RAMS WORKLOAD CALCULATION

RAMS calculates workload as a sum of the task duration times triggered during simulation, which is expressed as a percentage loading.

1 PEAK HOUR LOADING> 55% Sector is overloaded= 70% Capacity level is reached

2. SETTING SCENARIOS FOR RUNNING RAMS

a) Task listb) Task duration timesc) Actors (PC and/or EC)d) Appropriate “trigger”e) Appropriate “time offset”

Running RAMS

TASKS

SECTORISATION

TRAFFIC SAMPLE

ROUTE NETWORK

SIMULATIONS

BASIC FEATURES OF (FTS3)

1. Traffic sample- 28 June 2002, increased by 32%

2. ARNVbis Route network

3. Sectorisation was based on FTS2- 31 sectors

SCENARIO 1

1. TASK LIST IN FTS3 for CEATS (15)

2. NEW AVERAGE TASK DURATION TIMES(defined by interview)

3. NEW TASK DISTRIBUTION(defined by final questionnaire)

SIMULATION 1

BASIC FEATURES OF (FTS3) + SCENARIO 1

SIMULATION 2

BASIC FEATURES OF (FTS3) + SCENARIO 2

SCENARIO 2

1. NEW TASK LIST (31)(defined by survey)

2. NEW AVERAGE TASK DURATION TIMES(defined by interview)

3. NEW TASK DISTRIBUTION(defined by final questionnaire)

Comparison of workload

1. Workload increase ~70 % (PC)2. Workload decrease in one sector (PC)3. Workload decrease in six sectors (EC)

4. Similar workload results in most of the sectors (EC)

1. High workload increase ~130 % (PC)2. Workload results are increased by ~50% (EC)

FTS3 and Simulation 1

FTS3 and Simulation 2

FTS3 (PC and EC)

SECTOR OVERVIEW

100%

0%0%

91%

9% 0%

Simulation 2 (PC2 and EC2)

97%

3% 0%

78%

16%6%

Simulation 1 (PC1 and EC1)

94%

6% 0%

100%

0%0%

■ wk < 55% ■ 55% <wk < 70% ■ wk > 70%

SSRTS3, Simulation 1 and 2

√ Workload in SSRTS3 is defined by ISA method

√ Transformation of RTS workload values into FTS percentage values was made subjectively

√ Comparison of workload results was done in three sectors (C_5U, C_6U, C_8H)

√ Workload results after Simulation 2 were more aligned to estimated workload results in SSRTS3

WORKLOAD RATING

FTS3 ~100%

Simulation 1 ~ 35%

Simulation 2 ~ 30%FTS3 Sim1 Sim2

Planning Controller Executive Controller

EC in comparison with PC

SENSITIVITY ANALYSIS

Objective: Testing the influence of change of task duration times on controller workload using RAMS

Selected tasks:

1. Screen set up (19.64s)2. Conflict resolution (18.73s)3. Surveillance of A/C in sector (16.36s)4. Monitoring of all A/C influenced by an A/C climbing or descending (16.36s)

Simulation 3

√ The selected tasks (2) were included in the list with average maximum task duration times

√ It was used the same task list (31) with the same task duration times like in Simulation 2

Actors TASK NAMETask duration times in

simulation 3 (s)Task duration times in

simulation 2 (s)

PC Surveillance of A/C in sector 16.36 8.3

EC Surveillance of A/C in sector 20.45 10.4

PC Conflict resolution 18.91 10.3

EC Conflict resolution 23.64 14.8

SECTOR OVERVIEW

97%

3% 0%

78%

16%6%

Simulation 2 (PC2 and EC2)

94%

6% 0%

58%26%

16%Simulation 3 (PC3 and EC3)

■ wk < 55% ■ 55% <wk < 70% ■ wk > 70%

FTS3, Simulation 1, 2 and 3

Comparison of workload results for planning controller

0%

10%

20%

30%

40%

50%

60%

70%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Sectors

Pe

rce

nta

ge

load

ing FTS3-PC

Sim1-PC1

Sim2-PC2

Sim3-PC3

Comparison of workload results for executive controller

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Sectors

Pe

rce

nta

ge

load

ing FTS3-EC

Sim1-EC1

Sim2-EC2

Sim3-EC3

NATIONAL ACC

REASON FOR SERVEY

Differences in controller opinions

OBJECTIVES

Gathering data about minimum and maximum task duration times and actors who perform the tasks

PLACES OF RESEARCH

ACC Bratislava, ACC Budapest and ACC Vienna

RESULTS

1. Average task duration times are very similar in ACC Bratislava, Budapest and CRDS, except ACC Vienna

2. There is a group of tasks which has the same task distribution between controllers in each ACC and CRDS (13 tasks)

3. The tasks “Usage R&B” and “Usage MTCD” are performed in National ACC very rarely and task duration times for the group of “ Monitoring” tasks were not estimated by many controllers

CONCLUTIONS

√ The task duration times, number of the tasks and task distribution between controllers have high influence on RAMS workload calculations

√ The recommended standard task list for CEATS sectors consists of 24 tasks

√ The controllers’ answers are very various and significantly affected by different training of controller teams and air traffic procedures in each ACC, different equipment…

RECOMMENDATIONS

√ Observing controllers during performance of tasks in RTS environment

√ Conducting a similar survey by questionnaire but with participation of more controllers

√ Defining the other approach for transformation of workload values obtained in RTS into percentage values calculated in FTS

THANK YOU

Comparison of workload results for planning controller

0%

10%

20%

30%

40%

50%

60%

70%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Sectors

Perc

enta

ge lo

adin

g

FTS3-PC

Sim1-PC1

Sim2-PC2

Sim3-PC3

Comparison of workload results for executive controller

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

Sectors

Perc

enta

ge lo

adin

g

FTS3-EC

Sim1-EC1

Sim2-EC2

Sim3-EC3