Guide

The PRD format

MADETOOL reads a plain-text Product Requirements Document (format 1.7). The tables on this page are generated from the solver's schema (MADETOOL 1.0.0).

Line syntax

[section]                                   groups keys
key  = value unit REF | attr = value ...    fixed value / target
key >= value unit REF | ...                 requirement: must be AT LEAST
key <= value unit REF | ...                 requirement: must NOT EXCEED
# comment                                   to the end of the line

value : 12.5   3e-4   [300 200 150]   "quoted text"   WORD

Nothing in a PRD is ever evaluated: MADETOOL parses it with regular expressions only. Free text with spaces, # or | must be in double quotes.

Keywords

TBD - not known yet; never treated as zero. A required key that is TBD blocks the run.
NONE - no limit / not applicable, where allowed.
AUTO - the tool sizes or estimates the value, where allowed.
DEFAULT - use the model default (fidelity options).

References

Airspeeds must state TAS, EAS, CAS or IAS. Altitudes must state AGL or MSL; AGL is measured from environment.site_elevation.

Requirement attributes

Attribute	Values	Meaning
id	text	Requirement ID (default: section.key)
src	text	Source of the value; PLACEHOLDER/ASSUMED flags an unconfirmed value
note	text	Free note
type	HARD_LIMIT, MINIMUM, TARGET, PREFERENCE	Requirement type
prio	integer	Priority 1 (highest) .. 5
tol	tol	TARGET tolerance: % or - (relative) or a unit of the key (absolute)
alt	number with unit, or CRUISE, SITE	Altitude of the operating condition (or CRUISE / SITE)
isa_dev	number	ISA deviation of the operating condition
oat	number	Outside air temperature of the operating condition (alternative to isa_dev)
config	CLEAN, TAKEOFF, LANDING	Aerodynamic configuration

Requirement keys

Key	Operator	Default type	Unit (SI)	Required	Meaning
payload.mass_max	>=	MINIMUM	kg	Yes	Maximum payload mass the aircraft must carry (sets MTOW case)
payload.volume	>=	MINIMUM	m^3	No	Required internal payload volume
performance.endurance	>=	MINIMUM	s	No	Max endurance, NORMAL payload, take-off to landing, reserves excluded
performance.endurance_max_payload	>=	MINIMUM	s	No	Max endurance with MAX payload
performance.range	>=	MINIMUM	m	No	Max range (ground distance), NORMAL payload, take-off to landing, reserves excluded, with mission.headwind
performance.range_max_payload	>=	MINIMUM	m	No	Max range (ground distance) with MAX payload, with mission.headwind
performance.speed_max_level	>=	MINIMUM	m/s (TAS/EAS/CAS/IAS)	Yes	Max level-flight speed at MTOW, max continuous power
performance.speed_cruise	= >=	TARGET	m/s (TAS/EAS/CAS/IAS)	Yes	Normal cruise speed (used by FIXED cruise policy)
performance.speed_stall	<=	HARD_LIMIT	m/s (TAS/EAS/CAS/IAS)	No	Max allowed 1-g stall speed at MTOW in the stated configuration
performance.altitude_max	>=	MINIMUM	m (AGL/MSL)	Yes	Max operating altitude; service ceiling at MTOW must reach it
performance.altitude_cruise	=	TARGET	m (AGL/MSL)	Yes	Normal cruise (operating) altitude; also the DoD normal operating altitude
performance.climb_rate	>=	MINIMUM	m/s	No	Min steady rate of climb at MTOW, max continuous power
constraints.mtow	<=	HARD_LIMIT	kg	No	Max take-off mass limit
constraints.wingspan	<=	HARD_LIMIT	m	No	Max wing span
constraints.length	<=	HARD_LIMIT	m	No	Max overall length
constraints.height	<=	HARD_LIMIT	m	No	Max overall height
constraints.assembly_time	<=	PREFERENCE	s	No	Max field assembly time (not modelled in v0.1)
launch_recovery.takeoff_distance	<=	HARD_LIMIT	m	If launch_recovery.takeoff_method==RUNWAY	Take-off distance to clear environment.obstacle_height
launch_recovery.landing_distance	<=	HARD_LIMIT	m	If launch_recovery.recovery_method==RUNWAY	Landing distance from obstacle height
launch_recovery.parachute_descent_rate	<=	HARD_LIMIT	m/s	If launch_recovery.recovery_method==PARACHUTE	Max parachute descent rate
vtol.hover_tw_min	>=	HARD_LIMIT	-	If aircraft.vtol_code>=1	Min (max lift thrust / weight) at site conditions - control margin
vtol.hover_tw_oei_min	>=	HARD_LIMIT	-	No	Min (max lift thrust / weight) with the critical lift rotor inoperative while hover moments are trimmed, at site conditions (rotor-out capability; NONE = not required)
vtol.disk_loading_max	<=	HARD_LIMIT	Pa	No	Max lift-rotor disk loading (downwash limit)
stability.static_margin_min	>=	HARD_LIMIT	-	Yes	Min static margin (fraction of MAC) over the CG range
stability.static_margin_max	<=	PREFERENCE	-	No	Max static margin (trim drag / control power)
manufacturing.max_part_length	<=	HARD_LIMIT	m	No	Largest part that can be produced (mould/oven)
classification.dod_group	<=	HARD_LIMIT	-	No	Highest acceptable DoD UAS group

Units

Dimension	SI unit	Reference	Accepted tokens
dimensionless	-	-	- %
length	m	-	m km cm mm ft in nmi mi
altitude	m	AGL / MSL	m km cm mm ft in nmi mi
area	m^2	-	m^2 cm^2 mm^2 ft^2 in^2
volume	m^3	-	m^3 L mL cm^3 in^3 ft^3 USgal
mass	kg	-	kg g lb oz
time	s	-	s min h hr
speed	m/s	-	m/s km/h kt kn kts mph ft/s ft/min m/min
airspeed	m/s	TAS / EAS / CAS / IAS	m/s km/h kt kn kts mph ft/s ft/min m/min
acceleration	m/s^2	-	m/s^2 ft/s^2 g0
force	N	-	N kN kgf gf lbf
power	W	-	W kW hp PS
energy	J	-	J kJ MJ Wh kWh
specific_energy	J/kg	-	J/kg kJ/kg MJ/kg Wh/kg
energy_density	J/m^3	-	J/m^3 Wh/L MJ/L
pressure	Pa	-	Pa kPa hPa mbar N/m^2 kgf/m^2 lbf/ft^2 psi
density	kg/m^3	-	kg/m^3 kg/L g/cm^3 lb/ft^3
areal_density	kg/m^2	-	kg/m^2 g/m^2 lb/ft^2 oz/yd^2
temperature	K	-	K degC degF
temperature_delta	K	-	K degC degF
angle	rad	-	rad deg
angular_speed	rad/s	-	rad/s rpm
motor_kv	rad/(s*V)	-	rpm/V
voltage	V	-	V
current	A	-	A
charge	C	-	C Ah mAh
c_rate	1/s	-	C C-rate 1/h 1/s
bsfc	kg/J	-	kg/J g/kWh kg/kWh lb/(hp*h)
tsfc	kg/(N*s)	-	kg/(Ns) kg/(Nh) g/(kNs) lb/(lbfh)
power_per_weight	W/N	-	W/N W/kgf hp/lbf
specific_power	W/kg	-	W/kg kW/kg