diff --git a/experiments/generate_missions.py b/experiments/generate_missions.py
index 5a2e3f6c..098449a5 100755
--- a/experiments/generate_missions.py
+++ b/experiments/generate_missions.py
@@ -45,7 +45,7 @@ def generate(num_missions: int,
     config = build_config(speedup)
     mission_generator = RandomMissionGenerator(sut, initial, environment, config, max_num_commands=max_num_commands)
     resource_limits = ResourceLimits(num_missions)
-    missions = mission_generator.generate(None, resource_limits)
+    missions = mission_generator.generate(seed, resource_limits)
     with open(output_file, "w") as f:
         mission_descriptions = list(map(Mission.to_dict, missions))
         json.dump(mission_descriptions, f, indent=2)
diff --git a/experiments/generate_missions_templatebased.py b/experiments/generate_missions_templatebased.py
new file mode 100755
index 00000000..174b350c
--- /dev/null
+++ b/experiments/generate_missions_templatebased.py
@@ -0,0 +1,115 @@
+#!/usr/bin/env python3
+import json
+import yaml
+import logging
+import argparse
+import random
+
+from houston.mission import Mission
+from houston.generator.template_based import TemplateBasedMissionGenerator
+from houston.generator.resources import ResourceLimits
+
+from settings import sut, initial, environment, build_config
+
+
+logger = logging.getLogger("houston")  # type: logging.Logger
+logger.setLevel(logging.DEBUG)
+
+
+def setup_logging(verbose: bool = False) -> None:
+    log_to_stdout = logging.StreamHandler()
+    log_to_stdout.setLevel(logging.DEBUG if verbose else logging.INFO)
+    logging.getLogger('houston').addHandler(log_to_stdout)
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(description='Generates missions')
+    parser.add_argument('number_of_mission', type=int, action='store',
+                       help='number of missions to be generated.')
+    parser.add_argument('max_num_commands', type=int, action='store',
+                        help='maximum number of commands in a single mission.')
+    parser.add_argument('-t', type=str, action='store',
+                        help='template of the mission.')
+    parser.add_argument('-f', type=str, action='store',
+                        help='yaml file of mutants nad their templates.')
+    parser.add_argument('--speedup', action='store', type=int,
+                        default=1,
+                        help='simulation speedup that should be used')
+    parser.add_argument('--seed', action='store', type=int,
+                        default=1000,
+                        help='random seed to be used by random generator.')
+    parser.add_argument('--output', action='store', type=str,
+                        default='missions.json',
+                        help='the file where the results will be stored')
+    parser.add_argument('--verbose', action='store_true',
+                        default=False,
+                        help='verbose logging.')
+    return parser.parse_args()
+
+
+def generate(num_missions: int,
+             max_num_commands: int,
+             seed: int,
+             speedup: int,
+             template: str
+             ) -> None:
+    config = build_config(speedup)
+    mission_generator = TemplateBasedMissionGenerator(sut, initial, environment, config, max_num_commands=max_num_commands)
+    resource_limits = ResourceLimits(num_missions)
+    missions = mission_generator.generate(seed, resource_limits,
+                template=template)
+    return missions
+
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    setup_logging(args.verbose)
+    random.seed(args.seed)
+    with open(args.output, "w") as f:
+        pass
+    if args.t:
+        missions = generate(num_missions=args.number_of_mission,
+                 max_num_commands=args.max_num_commands,
+                 seed=args.seed,
+                 speedup=args.speedup,
+                 template=args.t)
+        mission_descriptions = list(map(Mission.to_dict, missions))
+    elif args.f:
+        templates = []
+        with open(args.f, "r") as f:
+            mutants = yaml.load(f, Loader=yaml.FullLoader)
+            for m in mutants:
+                template = m.get('mission-template')
+                if not template:
+                    continue
+                if isinstance(template, str):
+                    templates.append((template, args.number_of_mission, m['uid']))
+                elif isinstance(template, list):
+                    n_missions = args.number_of_mission
+                    for i, t in enumerate(template):
+                        if i == len(template)-1:
+                            templates.append((t, n_missions, m['uid']))
+                        else:
+                            r = random.randint(0, n_missions)
+                            templates.append((t, r, m['uid']))
+                            n_missions -= r
+        logger.info("Number of templates: %d", len(templates))
+        logger.info("AAAA %s", templates)
+        mission_descriptions = []
+        for template, num, uid in templates:
+            missions = generate(num_missions=num,
+                     max_num_commands=args.max_num_commands,
+                     seed=args.seed,
+                     speedup=args.speedup,
+                     template=template)
+            for n in missions:
+                new_dict = n.to_dict()
+                new_dict['mutant'] = uid
+                mission_descriptions.append(new_dict)
+    else:
+        raise Exception("Provide either -t or -f")
+
+    logger.info("Total number of missions: %d", len(mission_descriptions))
+    with open(args.output, "w") as f:
+        json.dump(mission_descriptions, f, indent=2)
diff --git a/houston/ardu/command_factory.py b/houston/ardu/command_factory.py
index 6e549211..ef978c45 100644
--- a/houston/ardu/command_factory.py
+++ b/houston/ardu/command_factory.py
@@ -27,8 +27,12 @@ def circle_based_generator(cls: Type[Command],
     destination = dist.destination(origin, heading)
 
     prob_zero = 0.1  # the probability of generating 0.0 as the parameter value
-    params['lat'] = destination.latitude if rng.random() >= prob_zero else 0.0
-    params['lon'] = destination.longitude if rng.random() >= prob_zero else 0.0
+    if rng.random() >= prob_zero:
+        params['lat'] = destination.latitude
+        params['lon'] = destination.longitude
+    else:
+        params['lat'] = 0.0
+        params['lon'] = 0.0
 
     command = cls(**params)
     return command
diff --git a/houston/command.py b/houston/command.py
index 6b97a049..fe5443d3 100644
--- a/houston/command.py
+++ b/houston/command.py
@@ -372,6 +372,21 @@ def generate(cls, rng: random.Random) -> 'Command':
         command = cls(**params)
         return command
 
+    @classmethod
+    def generate_fixed_params(cls,
+                              fixed_params: Dict[str, Any],
+                              rng: random.Random
+                              ) -> 'Command':
+        new_cmd = cls.generate(rng)
+        params = {}
+        for p in new_cmd:
+            if p.name in fixed_params.keys():
+                params[p.name] = fixed_params[p.name]
+            else:
+                params[p.name] = new_cmd[p.name]
+        command = cls(**params)
+        return command
+
 
 @attr.s(frozen=True)
 class CommandOutcome(object):
diff --git a/houston/generator/base.py b/houston/generator/base.py
index b7a452bb..80fd01d2 100644
--- a/houston/generator/base.py
+++ b/houston/generator/base.py
@@ -29,7 +29,7 @@ def __iter__(self):
         """
         return self
 
-    def __next__(self):
+    def __next__(self, **kwargs):
         """
         Requests the next mission from the mission generator.
         """
@@ -38,7 +38,7 @@ def __next__(self):
             g.tick()
             if g.exhausted():
                 raise StopIteration
-            mission = self.__generator.generate_mission()
+            mission = self.__generator.generate_mission(**kwargs)
             g.tick()
             g.resource_usage.num_missions += 1
             mission_num = g.resource_usage.num_missions
@@ -205,7 +205,8 @@ def record_outcome(self, mission, outcome, coverage=None):
 
     def generate(self,
                  seed: int,
-                 resource_limits: ResourceLimits
+                 resource_limits: ResourceLimits,
+                 **kwargs
                  ) -> List[Mission]:
         """
         Generate missions and return them
@@ -219,7 +220,7 @@ def generate(self,
             self.tick()
             # TODO use threads
             while True:
-                mission = stream.__next__()
+                mission = stream.__next__(**kwargs)
                 missions.append(mission)
         except StopIteration:
             logger.info("Done with generating missions")
diff --git a/houston/generator/template_based.py b/houston/generator/template_based.py
new file mode 100644
index 00000000..e884c868
--- /dev/null
+++ b/houston/generator/template_based.py
@@ -0,0 +1,192 @@
+from typing import Type, Dict, Callable, Optional, Any
+import logging
+import attr
+import re
+
+from .base import MissionGenerator
+from ..mission import Mission
+from ..system import System
+from ..state import State
+from ..environment import Environment
+from ..configuration import Configuration
+from ..command import Command
+from ..exceptions import HoustonException
+
+logger = logging.getLogger(__name__)   # type: logging.Logger
+logger.setLevel(logging.DEBUG)
+
+
+class FailedMissionGenerationException(HoustonException):
+    """
+    Thrown whenever the mission generation fails to follow the
+    template.
+    """
+
+
+@attr.s
+class CommandTemplate:
+    """
+    A CommandTemplate describes template for a set of commands.
+    """
+
+    cmd = attr.ib(type=str)
+    repeats = attr.ib(type=int)
+    params = attr.ib(type=Optional[Dict[str, Any]], default=None)
+
+    @staticmethod
+    def from_str(template_str: str) -> 'CommandTemplate':
+        """
+        Creates a CommandTemplate based on provided template
+        string. The template should take the following format:
+            `<COMMAND NAME>(<FIXED PARAMETERS>)^<NUMBER OF REPEATS>`
+        Example:
+            `TAKEOFF(alt: 10.3)^2` which means template is for
+            two `TAKEOFF` commands with parameter `alt` set to 10.3
+        Providing the parameters and number of repeats are
+        optional. By default, number of repeats is set to 1. If `*`
+        is provided as number of repeates, it will be dynamically
+        decided. If command name is provided as `.` it means any
+        possible command.
+        """
+
+        regex = r"(?P<cmd>[a-zA-Z\.\_]+)(?P<params>\(.*\))?(?P<repeats>\^[\d\*]*)?"  # noqa: pycodestyle
+        matched = re.fullmatch(regex, template_str.strip())
+        if not matched:
+            logger.error("Template is wrong %s", template_str)
+            return None
+        groups = matched.groupdict()
+        cmd = groups['cmd']
+        params = None
+        repeats = 1
+        if groups['params']:
+            pairs = groups['params'].strip()[1:-1].split(",")
+            params = {}
+            for pair in pairs:
+                splited = pair.split(":")
+                assert len(splited) == 2
+                params[splited[0].strip()] = eval(splited[1])
+        if groups['repeats']:
+            r = groups['repeats'][1:].strip()
+            if r == '*':
+                repeats = -1
+            else:
+                repeats = int(r)
+        return CommandTemplate(cmd, repeats, params)
+
+    def __str__(self):
+        s = "cmd: {}, params:{}, repeats: {}"
+        return s.format(self.cmd,
+                        self.params,
+                        self.repeats)
+
+
+class TemplateBasedMissionGenerator(MissionGenerator):
+    """
+    Given a template for intended missions, this generator
+    generates missions.
+    """
+
+    def __init__(self,
+                 system: Type[System],
+                 initial_state: State,
+                 env: Environment,
+                 config: Configuration,
+                 threads: int = 1,
+                 command_generators: Optional[Dict[str, Callable]] = None,
+                 max_num_commands: int = 10
+                 ) -> None:
+        super().__init__(system, threads, command_generators, max_num_commands)
+        self.__initial_state = initial_state
+        self.__env = env
+        self.__configuration = config
+
+    @property
+    def initial_state(self):
+        """
+        The initial state used by all missions produced by this generator.
+        """
+        return self.__initial_state
+
+    @property
+    def env(self):
+        """
+        The environment used by all missions produced by this generator.
+        """
+        return self.__env
+
+    def generate_command(self,
+                         command_class: Type[Command],
+                         params: Dict[str, Any]
+                         ) -> Command:
+        generator = self.command_generator(command_class)
+        if generator is None:
+            return command_class.generate_fixed_params(params,
+                                                       self.rng)
+        # g = generator.generate_action_without_state
+        # return g(self.system, self.__env, self.rng)
+        return g(self.rng)
+
+    def generate_mission(self, template: str):
+        """
+        A list of CommandTemplate strings separated by `-`
+        should be provided as template.
+        Example:
+            TAKEOFF(alt: 10.3)-.^*-LAND-.^1
+
+        raises:
+            FailedMissionGenerationException:
+                It failed to generate a mission for this
+                template.
+        """
+        command_templates = [CommandTemplate.from_str(t)
+                             for t in template.split("-")]
+        cmds_len = self.max_num_commands
+        cmds_len -= sum([c.repeats for c in command_templates
+                         if c.repeats > 0])
+        command_classes = list(self.system.commands.values())
+        for tries in range(50):
+            # try at most 50 times to generate a mission
+            commands = []
+            max_nonfixed_commands = cmds_len
+            try:
+                for ct in command_templates:
+                    r = ct.repeats
+                    if r <= 0:
+                        # number of repeats between 0 and max allowed
+                        r = self.rng.randint(0, max_nonfixed_commands)
+                    for _ in range(r):
+                        if commands:
+                            next_allowed = commands[-1].__class__.get_next_allowed(self.system)  # noqa: pycodestyle
+                        else:
+                            # everything is allowed
+                            next_allowed = [cc for cc in command_classes]
+
+                        if ct.cmd != '.':
+                            next_allowed = [cc for cc in next_allowed
+                                            if ct.cmd in cc.uid]
+
+                        if not next_allowed:
+                            if ct.repeats > 0:
+                                # logger.debug("So far %s", commands)
+                                commands = []
+                                raise FailedMissionGenerationException
+                            else:
+                                break
+                        params = ct.params or {}
+                        command_class = self.rng.choice(next_allowed)
+                        commands.append(self.generate_command(command_class,
+                                                              params))
+                        if ct.repeats <= 0:
+                            max_nonfixed_commands -= 1
+                break
+            except FailedMissionGenerationException:
+                logger.debug("Try %d failed", tries)
+                continue
+        if not commands:
+            raise FailedMissionGenerationException("Mission generation failed")
+        logger.debug("Generated mission: %s", commands)
+        return Mission(self.__configuration,
+                       self.__env,
+                       self.__initial_state,
+                       commands,
+                       self.system)