SLIDE 1
Importance of Tracking Requirements Importance of Tracking Requirements
EE40060‐1 2
Hatley Pirbhai with DOORS Hatley Pirbhai with DOORS Ed Fields - - PowerPoint PPT Presentation
Hatley Pirbhai with DOORS Hatley Pirbhai with DOORS Ed Fields - - PowerPoint PPT Presentation
Hatley Pirbhai with DOORS Hatley Pirbhai with DOORS Ed Fields efields@ieee.org efields@ieee.org Importance of Tracking Requirements Importance of Tracking Requirements EE40060 1 2 Top Level Requirements Top Level Requirements
SLIDE 2
SLIDE 3
Top‐Level Requirements Top Level Requirements
- Make ice
Make ice
– 50 pound blocks 4 blocks/day 6 days/week – 4 blocks/day, 6 days/week – System must be able to grow to produce 200 blocks/day blocks/day
- Monitor power usage
l d d k h f
- Ice loaded into trucks in the morning for
delivery
3
SLIDE 4
Model Functions Model Functions
- Hatley‐Pirbhai methodology
Hatley Pirbhai methodology
– Developed by Imtiaz Pirbhai and Derek Hatley as an outgrowth from in the late 1980s an outgrowth from in the late 1980s. – Imtiaz Pirbhai was under contract to Hughes Aircraft Company 1991‐1994. Died after first year. Aircraft Company 1991 1994. Died after first year.
- Using TurboCASE as H‐P tool.
4
SLIDE 5
Context Diagram Context Diagram
Water Source water Make and load ice .0 Truck blocks
- f ice
truck water
- n/off
Status
- Context Diagram shows system interface with the
‘world’
- Water flows into the system with on/off control
I t f th t ith th t
- Ice comes out of the system with the system
having some knowledge of the truck
5
SLIDE 6
Requirements Table Requirements Table
1 Make ice 2 Monitor Power Usage 3 Load ice onto trucks
6
SLIDE 7
Extended Numbering to allow h Paragraph Structure
1 Introduction 2 References 3 Requirements 3 1 Make ice 3.1 Make ice 3.2 Monitor Power Usage 3.3 Load ice onto trucks
7
SLIDE 8
Decompose Context Level Decompose Context Level
blocks
- f ice
Make Ice .1 Load Ice
- nto
trucks .3 water blocks
- f ice
water Monitor .2 truck St t water
- n/off
Power Usage power Status power usage per block of block of ice
8
SLIDE 9
Continue Decomposition, process 3 Continue Decomposition, process 3
1 Check position
- f truck
.1 truck Status truck is ready for ice slide block
- f ice onto
truck .2 blocks
- f ice
.3 block loaded count and total blocks
- n truck
.3 truck is ready to leave
9
SLIDE 10
DOORS Table DOORS Table
1 Introduction 2 References 3 Requirements 3 Requirements 3.1 Make ice
The main purpose of this process is to freeze water in 50 lb. blocks. The molds have to be filled with water, the water frozen, the blocks removed from the mold, and then stored for loading onto trucks for delivery.
3.2 Monitor Power Usage
This function measures the amount of power used by the system, totals the amount of power from one day to the next over 24 hours, and reports this value.
3.3 Load ice onto trucks
When truck is in proper position at loading dock move ready ice onto truck and make sure it is secure When truck is in proper position at loading dock, move ready ice onto truck and make sure it is secure. Only load the appropriate amount of ice onto the truck.
3.3.1 Check position of truck
Verify a truck is in a valid position for loading ice. Also insure the truck has enough available cargo capacity for the desired amount of ice.
3.3.2 Slide block of ice onto truck
Move blocks of ice onto the truck and secure the load.
3.3.3 Count and total blocks on truck
Verify the correct number of blocks are loaded onto the truck. Notify truck driver the loading of the truck is complete
10
is complete.