use cases

Use Case (UC) "Brew Coffee"

American coffee, drip coffee

Short description
        UC describes the brewage of coffee using a coffee machine (percolator) Q-Coffee3000
Actor
        CM (Coffee Maker) = the person who makes the coffee
Preconditions
        No fresh (drinkable) coffee is available
The coffeepot is empty
The coffee machine (percolator) is ready-to-operate
Power Supply is available
Main Flow (M)
  M1     The CM fills water into the water tank (A1)
  M2     The CM opens the filter box and inserts a new filter (A2a, A2b)
  M3     he CM fills in roast and ground coffee into the filter and closes the filter box (A3)
  M4     The CM checks the correct position of the coffeepot => is the coffeepot located in the designated position? (A4)
  M5     The CM starts the coffee machine (percolator) (A5a)
  M6     The coffee machine (percolator) brews a fresh and drinkable coffee (A6a)
  M7     The UC ends
Alternate Flows (A)
  A1     The water has been filled in already (M2)
  A2 a   A used filter is in the filter box - The CM removes the used filter.
Repeat at (M2)
  A2 b   A new filter has been inserted already. - Continue at (M3)
  A3     The roast and ground coffee has been filled in already into the new filter. The CM closes the filter box.
Continue at (M4)
  A4     The coffeepot is not located on the designated position. The CM places the coffeepot on the designated position.
Continue at (M5)
  A5 a   The coffee machine (percolator) does not respond. The CM reads the manual and tries to solve the problem.
  A5 a 1 The CM cannot solve the problem. The CM stops the procedure and contacts the support.
  A5 a 2 The CM solves the problem using the manual
Continue at (M6)
  A6 a   A power breakdown occurs. The CM waits until reactivation
  A6 a 1 The coffee has been cooled off in the meanwhile. The CM pours the coffee away
Continue at (M1)
  A6 a 2 he coffee machine (percolator) continues automatically.(M7)
Post conditions
        A fresh and drinkable coffee is brewed.
Constraints
        Coffee quantity: 1 spoonful coffee per Cup of water or at one’s discretion
Water quantity: 1 cup per person (1 cup = see water tank marker)
Maximal water quantity: water tank „max“-mark has to be considered
The fresh brewed coffee has to be drinkable.
The coffee temperature is between 50° und 70° C…
Business Objects
        Coffee machine (percolator)
Water tank
Coffeepot
Filter box
Roast and ground coffee
Fresh and drinkable coffee
Coffee filter
Water
Reference documents
        Manual of coffee machine (percolator) Q-Coffee3000
Technical specification of coffee machine (percolator) Q-Coffee3000