Question

An analysis of the emergency services responding to a hazardous chemical incident needs to be performed. In the scenario analyzed, some youths had broken into a farm and disturbed some chemicals in sacking. One of the youths had been taken to the hospital with respiratory problems, whilst the others were still at the scene. The police were sent to investigate the break-in at the farm. They called in the fire service to identify the chemical and clean up the spillage. The overall analysis shows four main sub-goals: receive notification of an incident, gather information about the incident, deal with the chemical incident, and resolve the incident. Perform a hierarchical task analysis for the above scenario. [Hint your answer should demonstrate all features of HTA Notations such as Selection, Iteration, Sequence and Unit task]

Answer 1

Explanation:

Task Analysis:

Task analysis can be described as the aggregation of  methods to analyze jobs of people in terms of :

• what people do
• what things they work with
• what they must know

Approaches to task analysis:

• Task decomposition – splitting task into ordered subtasks
• Knowledge based techniques – what the user knows about the task and how it is organized
• Entity/object based analysis – relationships between objects, actions and the people who perform them
• Various notations/techniques

General Method:

• observe
• collect unstructured lists of words and actions
• organize using notation or diagrams

One of the common methods of task analysis is HTA.

Hierarchical Task Analysis ( HTA ) :

A structured, objective approach to describing users’ performance of tasks, hierarchical task analysis originated in human factors. In its most basic form, a hierarchical task analysis provides an understanding of the tasks users need to perform to achieve certain goals. Originally developed in response to the need for greater understanding of cognitive tasks, HTA involves describing the activity under analysis in terms of hierarchy of goals, sub–goals, operations, and plans. The end result is an exhaustive description of task activity.

In its most basic form, a hierarchical task analysis provides an understanding of the tasks users need to perform to achieve certain goals. You can break down these tasks into multiple levels of subtasks. In user experience, you can use hierarchical task analysis to describe the interactions between a user and a software system. When designing a new system, hierarchical task analysis lets you explore various possible approaches to completing the same task. When analyzing an existing system, it can help you to optimize particular interactions.

Applying Hierarchical Task Analysis to User Experience :

Hierarchical task analysis requires a detailed understanding of users’ tasks. You can achieve this understanding by:

• identifying users’ primary goals
• detailing the steps users must perform to accomplish their goals
• optimizing these procedures

Steps to apply HTA :

A. Starting the analysis

• specify area of work or main task
• subdivide into four to eight subtasks, specify subtasks in terms of objectives (should cover entire area)
• draw subtasks as layered plans. ensure logical and technical correctness

B. Progressing the analysis

•      decide necessary level of detail and when to end decomposition
•      choose between depth-first or breadth-first analysis (or alternate between the two)
•      use diagrammatic form and numbering convention

C. Finalizing the analysis

• check for consistent decompositions and numbering. perhaps also produce a written account in addition to decomposition diagram.
• have analysis checked by someone familiar with task but not involved in decomposition analysis

In the light of the above discussions, the HTA for the given scenario for the emergency services responding to a hazardous chemical incident can be outlined as follows:

The Solution to the given Scenario:

In the light of the above discussions, the HTA for the given scenario for the emergency services responding to a hazardous chemical incident can be outlined as follows:

A. Receive notification of an incident:

1. Record the location of the incident

2. Record the details of the informer - name, address, contact details

3. Record the date and time of the intimation

B. Gather information about the incident:

1. Record the date and time of the incident

2. Record the persons involved in the incident

a. the persons discovering the incident with date and time

b. the persons causing the incident with reasons, if any

c. the persons affected by the incident and the casualties caused

C. Deal with the chemical incident:

1. Safeguard the premises by eliminating chances of further hazards

2. Collect sample and analyse the chemicals involved in the incident

3. Observe the nature of damage caused by the chemicals:

a. to humans

b. to other living beings

c. to other substances

4. Collect all relevant samples & data pertinent to further analysis for root cause

5. Clean up the chemical spillage

6. Run thorough checks to ensure the hazard has been totally eliminated

D. Resolve the incident:

1. Analyse and identify the chemicals causing the hazard

2. Find out the root cause resulting in the hazard

3. Ensure safety and clearance of the premises damaged by the chemicals

4. Take appropriate steps to build awareness so that such hazard can be avoided in the future

5. Document all the findings and observations and share the same with the concerned authority for further necessary action

6. Develop safety and preventive awareness in the neighbothood and surroundings to avoid repetation or future mishaps

This concludes the HTA  analysis of the emergency services responding to the hazardous chemical incident in the given scenario. Please do not forget to like the answer if it helps you. Thank you.