Any model is fine, but let me explain the problem using an ExampleFile in E+ v9-4-0 for simplicity.
This idf file is a slightly revised version of HVACTemplate-5ZoneVAVFanPowered.idf from ExampleFiles. Originally there were 5 zones, but I deleted 4 HVACTemplate:Zone:VAV:FanPowered because they worked fine. Now there is only one zone (SPACE5-1) with HVACTemplate:Zone:VAV and HVACTemplate:System:VAV. I want to focus on them.
Besides, I added Zone Air Terminal Outdoor Air Volume Flow Rate in Output:Variable, and just ran the simulation. I got the results for 2 days in winter and summer. The charts below show outdoor air flow rate.
I don't know why the actual outdoor air flow rate is not constant and below the design outdoor air flow rate.
In HVACTemplate:Zone:VAV, Outdoor Air Method is flow/person and the value is fixed to 0.00944 m3/s per person. In People, Number of People is fixed to 20, so I think the outdoor air flow rate should be constant at 0.00944 x 20 = 0.1888m3/s (the orange dashed lines in the charts). But the actual outdoor air flow rate is quite different from 0.1888m3/s, especially when heating.
At first, Minimum Outdoor Air Flow Rate in HVACTemplate:System:VAV was set to autosize, so I changed it to the exact value 0.1888, but in vain.
People has an occupancy schedule with different fractions for different time zones, but I believe that flow/person for Outdoor Air Method is not affected by occupancy schedule.
I know that acrording to Engineering Reference, VAV doesn't work as VAV when heating (although I'm not convinced why this is the default setting). But is there any way to keep minimum outdoor air flow rate as I want? 
For your reference, below is the input for HVACTemplate:Zone:VAV and HVACTemplate:System:VAV. The fraction of Min OA Schedis 1 from 9:00 to 21:00, so there is nothing strange about it.
HVACTemplate:Zone:VAV,
SPACE5-1, !- Zone Name
VAV Sys 1, !- Template VAV System Name
All Zones, !- Template Thermostat Name
autosize, !- Supply Air Maximum Flow Rate {m3/s}
, !- Zone Heating Sizing Factor
, !- Zone Cooling Sizing Factor
Constant, !- Zone Minimum Air Flow Input Method
0.3, !- Constant Minimum Air Flow Fraction
, !- Fixed Minimum Air Flow Rate {m3/s}
, !- Minimum Air Flow Fraction Schedule Name
flow/person, !- Outdoor Air Method
0.00944, !- Outdoor Air Flow Rate per Person {m3/s}
0.0, !- Outdoor Air Flow Rate per Zone Floor Area {m3/s-m2}
0.0, !- Outdoor Air Flow Rate per Zone {m3/s}
HotWater, !- Reheat Coil Type
, !- Reheat Coil Availability Schedule Name
Reverse, !- Damper Heating Action
, !- Maximum Flow per Zone Floor Area During Reheat {m3/s-m2}
, !- Maximum Flow Fraction During Reheat
, !- Maximum Reheat Air Temperature {C}
, !- Design Specification Outdoor Air Object Name for Control
, !- Supply Plenum Name
, !- Return Plenum Name
None, !- Baseboard Heating Type
, !- Baseboard Heating Availability Schedule Name
autosize, !- Baseboard Heating Capacity {W}
SystemSupplyAirTemperature, !- Zone Cooling Design Supply Air Temperature Input Method
, !- Zone Cooling Design Supply Air Temperature {C}
, !- Zone Cooling Design Supply Air Temperature Difference {deltaC}
SupplyAirTemperature, !- Zone Heating Design Supply Air Temperature Input Method
50.0, !- Zone Heating Design Supply Air Temperature {C}
; !- Zone Heating Design Supply Air Temperature Difference {deltaC}
HVACTemplate:System:VAV,
VAV Sys 1, !- Name
FanAvailSched, !- System Availability Schedule Name
autosize, !- Supply Fan Maximum Flow Rate {m3/s}
autosize, !- Supply Fan Minimum Flow Rate {m3/s}
0.7, !- Supply Fan Total Efficiency
600, !- Supply Fan Delta Pressure {Pa}
0.9, !- Supply Fan Motor Efficiency
1, !- Supply Fan Motor in Air Stream Fraction
ChilledWater, !- Cooling Coil Type
, !- Cooling Coil Availability Schedule Name
, !- Cooling Coil Setpoint Schedule Name
12.8, !- Cooling Coil Design Setpoint {C}
HotWater, !- Heating Coil Type
, !- Heating Coil Availability Schedule Name
, !- Heating Coil Setpoint Schedule Name
10.0, !- Heating Coil Design Setpoint {C}
0.8, !- Gas Heating Coil Efficiency
0.0, !- Gas Heating Coil Parasitic Electric Load {W}
None, !- Preheat Coil Type
, !- Preheat Coil Availability Schedule Name
, !- Preheat Coil Setpoint Schedule Name
, !- Preheat Coil Design Setpoint {C}
0.8, !- Gas Preheat Coil Efficiency
0.0, !- Gas Preheat Coil Parasitic Electric Load {W}
autosize, !- Maximum Outdoor Air Flow Rate {m3/s}
0.1888, !- Minimum Outdoor Air Flow Rate {m3/s}
FixedMinimum, !- Minimum Outdoor Air Control Type
Min OA Sched, !- Minimum Outdoor Air Schedule Name
DifferentialDryBulb, !- Economizer Type
NoLockout, !- Economizer Lockout
19, !- Economizer Upper Temperature Limit {C}
4, !- Economizer Lower Temperature Limit {C}
, !- Economizer Upper Enthalpy Limit {J/kg}
, !- Economizer Maximum Limit Dewpoint Temperature {C}
, !- Supply Plenum Name
PLENUM-1, !- Return Plenum Name
DrawThrough, !- Supply Fan Placement
InletVaneDampers, !- Supply Fan Part-Load Power Coefficients
CycleOnAnyZoneFansOnly, !- Night Cycle Control
, !- Night Cycle Control Zone Name
None, !- Heat Recovery Type
0.70, !- Sensible Heat Recovery Effectiveness
0.65, !- Latent Heat Recovery Effectiveness
None, !- Cooling Coil Setpoint Reset Type
None, !- Heating Coil Setpoint Reset Type
None, !- Dehumidification Control Type
, !- Dehumidification Control Zone Name
60.0, !- Dehumidification Setpoint {percent}
None, !- Humidifier Type
, !- Humidifier Availability Schedule Name
0.000001, !- Humidifier Rated Capacity {m3/s}
2690.0, !- Humidifier Rated Electric Power {W}
, !- Humidifier Control Zone Name
30.0, !- Humidifier Setpoint {percent}
NonCoincident, !- Sizing Option
, !- Return Fan
, !- Return Fan Total Efficiency
, !- Return Fan Delta Pressure {Pa}
, !- Return Fan Motor Efficiency
, !- Return Fan Motor in Air Stream Fraction
; !- Return Fan Part-Load Power Coefficients
