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Analysis Procedures. Mission Analysis Function Determination Function Allocation Task Description / Identification Task Analysis. Mission Analysis (System Requirements Analysis). What is the system supposed to accomplish? The analyst/designer needs to know - Specific Goals
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Analysis Procedures • Mission Analysis Function Determination • Function Allocation • Task Description / Identification • Task Analysis
Mission Analysis (System Requirements Analysis) • What is the system supposed to accomplish? • The analyst/designer needs to know - • Specific Goals • Required Outputs • Required Inputs • System Capacities and Performance Requirements • Operating Environmental Factors • Constraints on System Operation
Mission Analysis Tools • Mission Profile Graphic Description (Example - Flight Profile) • Mission Scenario Verbal Description - Summarizes typical assumptions, environments, operations. • Mission Segment Time period of coherent activities with definite beginning and ending points.
Importance of Function & Task Analyses • Evaluate Human Factors Implications • Design Requirements and Constraints • Workload Implications • Notes: • 1. Decompose to level where functions to be performed • by system can be identified. • 2. Be careful that proposed design solution does not • appear to be a function description.
Determination of Functions • Identify and Describe Functions - by • Determining Function Inputs and Outputs • Establishing Functional Performance Criteria • Preparing Functional Flow Diagrams • Function Examples: • To Detect • To Repair • To Analyze • Functions - Can be • Instantaneous (Start Engine) • Prolonged ( Monitor Radar Screen) • Complex (Analyze Equipment Malfunction)
Function Performance Criteria • Yardstick used to measure/predict whether or not thesystem/function meets the performance requirements. • Criteria can range from gross to finely detailed. • Functional Performance Criteria must be stated in terms ofthose test results that must be satisfied in order for thesystem/function to meet the performance requirements. • Provides the basis for preparing the Functional Flow Diagram.
Functional Flow Diagram • Determine the functions that have already been allocated. • Describe the various different ways that each unallocatedfunction might be accomplished. • Establish the weighting criteria for comparing the alternatives. • Compare each of the alternative against one another. • Select the most cost-effective design.
Task Description / Identification • Examine each selected design alternative. • List in sequence all the actions that must be performed to accomplish thefunctional element. • Categorize actions in terms of whether they areoperator or maintainer activities; and by thehardware/software subsystems to which they belong. • Describe each action in terms of a behavioral verb (see next slide). • Break tasks down into subordinate tasks by specifying inputs and outputsfor each task/subtask.
Behavioral Verbs • ActionExample - to turn on, to monitor, to disassemble • Equipment Acted UponExample - switch, motor, display • Consequence of ActionExample - voltage display stabilized • Stimulus that Initiates the ActionExample - pilot’s command • Feedback Information Resulting form Task PerformanceExample - aircraft heading 320 degrees • Criterion of task accomplishmentExample - vehicle stopped/parked with 3 feet of marker
Task Analysis • Design Questions • Manning Questions • Training Questions • Test and Evaluation Questions
Design Questions • What tasks need to be performed? • How critical is each task? • In what sequence must the tasks be performed? • What control activations are required? etc, etc, etc, etc
Manning Questions • How many people are required to perform the task? • What skill levels are required?
Training Questions • On what behavioral dimensions are the tasks performed? • How difficult or complex is each task? • What information is required to perform the task?etc, etc, etc, etc
Test and Evaluation Questions • What are the performance criteria for the task or job?