This case analysis is based on hekate process.
The ARD process can be easily explained using the following example. It is a reworked Thermostat case. The main problem described here is to create a temperature control system for an office. The design process is shown below.
Rule: 1 if the day is Monday or the day is Tuesday or the day is Wednesday or the day is Thursday or the day is Friday then today is a workday Rule: 2 if the day is Saturday or the day is Sunday then today is the weekend Rule: 3 if today is workday and the time is 'between 9 am and 5 pm' then operation is 'during business hours' Rule: 4 if today is workday and the time is 'before 9 am' then operation is 'not during business hours' Rule: 5 if today is workday and the time is 'after 5 pm' then operation is 'not during business hours' Rule: 6 if today is weekend then operation is 'not during business hours' Rule: 7 if the month is January or the month is February or the month is December then the season is summer Rule: 8 if the month is March or the month is April or the month is May then the season is autumn Rule: 9 if the month is June or the month is July or the month is August then the season is winter Rule: 10 if the month is September or the month is October or the month is November then the season is spring Rule: 11 if the season is spring and operation is 'during business hours' then thermostat_setting is '20 degrees' Rule: 12 if the season is spring and operation is 'not during business hours' then thermostat_setting is '15 degrees' Rule: 13 if the season is summer and operation is 'during business hours' then thermostat_setting is '24 degrees' Rule: 14 if the season is summer and operation is 'not during business hours' then thermostat_setting is '27 degrees' Rule: 15 if the season is autumn and operation is 'during business hours' then thermostat_setting is '20 degrees' Rule: 16 if the season is autumn and operation is 'not during business hours' then thermostat_setting is '16 degrees' Rule: 17 if the season is winter and operation is 'during business hours' then thermostat_setting is '18 degrees' Rule: 18 if the season is winter and operation is 'not during business hours' then thermostat_setting is '14 degrees'
The seasons ARE correct, the Author lives in Australia.
We model the system aiming at matching the original rules.
First, it is stated that there is a system to be designed which is described by
a single conceptual attribute Thermostat.
It is so called level 0 of the design.
Refining knowledge about what is the purpose of the system makes a transition to the diagram at level 1; it is a finalization.
It is stated that the thermostat controls temperature and this control has something to do with time.
That is why Thermostat is finalized into Time and Temperature.
Furthermore, at level 2, it is stated that Temperature
depends on Time: there are two properties identified in the
system and a functional dependency between them.
The design process continues, through splits and/or finalizations, until all physical attributes (indicated with lower case letters) are identified and relationships among them are stated which is presented at level 8.
The whole process is shown below:
| ARD diagram | Corresponding THP | VARDA model |
|---|---|---|
| <graphviz file=“hekate:therm-a0.dot”></graphviz> | ard_att_add('Thermostat'), ard_property_add(['Thermostat']) | |
| <graphviz file=“hekate:therm-a1.dot”></graphviz> | <graphviz file=“hekate:therm-t1.dot”></graphviz> | ard_att_add('Time'), ard_att_add('Temperature'), ard_finalize(['Thermostat'], ['Time','Temperature']) |
| <graphviz file=“hekate:therm-a2.dot”></graphviz> | <graphviz file=“hekate:therm-t2.dot”></graphviz> | ard_split(['Time','Temperature'],[ ['Time'],['Temperature']], [ [ ['Time'],['Temperature']]]) |
| <graphviz file=“hekate:therm-a3.dot”></graphviz> | <graphviz file=“hekate:therm-t3.dot”></graphviz> | ard_att_add('Date'), ard_att_add('Hour'), ard_att_add(season), ard_att_add(operation), ard_finalize(['Time'],['Date','Hour',season,operation]) |
| <graphviz file=“hekate:therm-a4.dot”></graphviz> | <graphviz file=“hekate:therm-t4.dot”></graphviz> | ard_split(['Date','Hour',season,operation],[ ['Date','Hour'],[season,operation]],[ [ ['Date','Hour'], [season,operation]],[ [season,operation],['Temperature']]]) |
| <graphviz file=“hekate:a5f.dot”></graphviz> | <graphviz file=“hekate:t5f.dot”></graphviz> | ard_split([season,operation],[ [season],[operation]],[ [ ['Date','Hour'],[season]],[ ['Date','Hour'],[operation]],[ [season],['Temperature']],[ [operation], ['Temperature']]]) |
| <graphviz file=“hekate:a6f.dot”></graphviz> | <graphviz file=“hekate:t6f.dot”></graphviz> | ard_split(['Date','Hour'],[ ['Date'],['Hour']],[ [ ['Date'],[season]],[ ['Date'],[operation]],[ ['Hour'],[operation]]]) |
| <graphviz file=“hekate:a7f.dot”></graphviz> | <graphviz file=“hekate:t7f.dot”></graphviz> | ard_att_add(day), ard_att_add(month), ard_att_add(today), ard_finalize(['Date'],[day,month,today]) |
| <graphviz file=“hekate:a8f.dot”></graphviz> | <graphviz file=“hekate:t8f.dot”></graphviz> | ard_split([day,month,today],[ [month],[day,today]],[ [ [month],[season]],[ [day,today],[operation]]]) |
| <graphviz file=“hekate:a9f.dot”></graphviz> | <graphviz file=“hekate:t9f.dot”></graphviz> | ard_split([day,today],[ [day],[today]],[ [ [day],[today]],[ [today],[operation]]] |
| <graphviz file=“hekate:a10f.dot”></graphviz> | <graphviz file=“hekate:t10f.dot”></graphviz> | ard_att_add(hour), ard_finalize(['Hour'],[hour]), ard_att_add(thermostat_settings), ard_finalize(['Temperature'],[thermostat_settings]) |
VARDA can automatically optimize the diagram, by re/collapsing the lowest ARD using TPH.
The subsequent optimized ARD levels (as recreated by VARDA) are given below:
The Transformation Process History diagram is given below:
See therm-model.pl in varda
XTT prototype generated by VARDA:
check if:
