Functions Analysis
What
A description of the functionality in the blocks.
How
The dish
Functions
Ingredients
Process
With the list of Function Candidates it is time to assess each candidate.
Consider each candidate and determine if the candidate fulfils a specific task enabling an actor's usage of the system-to-be. Only function candidates that serve actors should be included in the final list. Functions that do not provide anything to an actor are possibly functions that should be part of a class implementation and consequently not part of the function list.
Describe each function briefly. Describe the function to a level that enables another developer to understand the exact purpose of the function.
Classify each function according to its type (Updating, Signalling, Reading, Calculating).
Estimate the complexity of each function. Use for example the categories: Simple, Medium, Complex and Very Complex. Functions with a high complexity should be described in more details.
If specific mathematics is needed for the function, include the necessary formulas, if available, together with the description.
A high customer involvement is still recommended during this process. The customer may have any mathematics available. The customer is the best source to information about data manipulation in the system-to-be.
Why
Please see the Function Candidates Analysis#Why.
Example
TotalElectricPowerProduction (period)
Description: Calculates the power production from the Solar Cells for the period specified. For each period of 4.6 seconds the production in watts is stored - hence summarise the production covering the period.
Type: Calculating
Complexity: Medium
ViewSettings
Reads out the previously stored settings for the system.
Type: Reading
Complexity: Simple
SetTemperatures (daytemp, starttime, nighttemp, starttime, weekday)
Stores the temperatures the user wants in the room. The period covering one specific weekday is divided into day and night settings.
Type: Updating
Complexity: Simple
Used In
The Functions is used throughout the rest of the design of the system-to-be. Especially in the Subsystem Design the Functions is a major part. You may want to go to System Dynamics from here.
