Problem using Parallel processing.

I have a challenge I am facing at the moment and I need some new ideas.

I am trying to run this code using parallel computing, however I am having error using parfor due to

the inclusion of global variable as such i am considering using spmd however i don't seem to know how to

to go about it. can I use parfor if not then how can i use spmd.

global environment_wavedirection; %Using global to define the wave direction

dTheta = 45;

MaxTheta=360-dTheta; %The max angle not including 360 degree

kn = 1; %Define the load case exposure for the number of caese

D_total = 0; %Define the initial value of Total fatigue

WaveDirection = environment_wavedirection; %wave direction for each time

RefCurrentDirection = environment_wavedirection;

WindDirection = environment_wavedirection;

% Run the global wave direction from 0 to max angle with dtheta as difference

for environment_wavedirection = 0:dTheta:MaxTheta

%% Run both the statics and dynamics analysis

model.CalculateStatics; %Run the static analysis in preparation for dynamics

model.RunSimulation; %Run the Dynamic simulation for result extraction and

% for preparation of fatigue analysis

% Save each simulation based on the inputed angle in sequence

model.SaveSimulation(sprintf('scrresponse%d.sim',environment_wavedirection));

% Call for fatigue analysis to commence the process

fatigue = ofxFatigueAnalysis;

% %fatigue.Load('waomoscrlengthfatigue.ftg')

% %or

% %ofxFatigueAnalysis.Load('waomoscrlength.sim')

% Define the General parameter before starting the fatigue analysis

LoadCaseCount = 2; %Define the number of load cases for the analysis

LoadCaseFileName(1) = case01(x); %Define the case file in the folder

% %which calls and run and save the simulation file

%from which results are extracted, while maintaining

% %the global variable inside the casefile

LoadCaseLineName(1) = ('SCRmodel'); %Define the name of the line as found in the casefile

PeriodFrom(1) = Ti; %Define the initial time of the asefile

PeriodTo(1) = Tf; %Define the final time of the casefile

%Define the exposed time accoding to the number for loop

ExposedTime1 = 5768*[0.2326,0.2552,0.0234,0.0014,0.0062,0.0868,0.2108,0.1836];

%Define the actual exposure time base on Kn according to the loop

LoadCaseExposureTime(1) = ExposedTime1(kn);

LoadCaseFileName(2) = case02(x); %Define the case file in the folder

% %which calls and run and save the simulation file

%from which results are extracted, while maintaining

% %the global variable inside the casefile

LoadCaseLineName(2) = ('SCRmodel'); %Define the name of the line as found in the casefile

PeriodFrom(2) = Ti; %Define the initial time of the asefile

PeriodTo(2) = Tf; %Define the final time of the casefile

%Define the exposed time accoding to the number for loop

ExposedTime2 = 19898.8*[0.2326,0.2552,0.0234,0.0014,0.0062,0.0868,0.2108,0.1836];

%Define the actual exposure time base on Kn according to the loop

LoadCaseExposureTime(2) = ExposedTime2(kn);

D_fat = xlsread(result,1,'B8'); %read the D_fat from the first.

D_total = D_total + D_fat; %add D_fat to the existing D_total

kn = kn+1; %use kn+1 as the next step

end