CS823 – Reasoning for Intelligent Agents
Computer and Information Sciences
University of Strathclyde
Created June 2023
By Dr Andrew Abel
Redit Assignment – PDDL Building – Worth 100% of Overall Mark
There are 3 parts to this assignment, a non-temporal model, a temporal model, and a set of written
questions.
Submission deadline: 04/08/23
Online submission through MyPlace
Background: Island Construction
You have been hired to model and create automatic plans for a construction company. Island Construction
have a new project, specialising in constructing houses on the mysterious Isla de Planificación. Your task is
to use PDDL to model their work environment and all the agents within it, and to create valid plans. Isla de
Planificación is shown below:
All houses require raw materials, and they can be found in the following depots:
(0,0) Bricks
(0,1) Wood
CS823 – Reasoning for Intelligent Agents
Computer and Information Sciences
University of Strathclyde
Created June 2023
By Dr Andrew Abel
(4,2) Glass
(2,0) Slate
The other locations on the map can potentially have houses built on them, depots can not have houses
constructed on them: (1,2) (2,1) (2,3) (2,4) (3,2) (3,3) (4,3).
Houses require the following resources to be constructed:
1 x Bricks, 1 x Wood, 1 x Glass, 1 x Slate.
There are a number of agents in the company. The company has 2 delivery trucks, which can travel to any
location or depot, and can each carry 1 item at a time, 1 architect, who designs the house, and 1 builder,
who constructs the house. The architect and builder can only travel to locations, not depots, and all agents
must follow the roads to travel between locations. The roads are all two way.
The architect can design the house, but only when there is 1 x wood on the site. The architect can
travel to any location, but not a depot. Designing the house does not use any wood. The builder
starts at location (3,3).
The builder can build the house, but only when there is a designed house on the site. The builder
can travel to any location, but not a depot. When the house is built, all resources are used up. The
builder starts at location (1,2).
The delivery trucks can travel to any depot or location. They can store any type of item, but can only
store 1 item at a time (i.e. they can only carry a single wood). They can load at a depot, or unload at
a location. All delivery trucks start at location (2,1).
We make the assumption that any number of agents may occupy a location or depot simultaneously, and
that the depots produce an unlimited number of resources.
Part 1: Non-Temporal Plan (35 marks)
Use the above information to create a PDDL file for the domain and the problem.
You should correctly identify the agents, functions, and program the actions with suitable conditions. Here,
you do not need to worry about temporal actions.
The goal is to construct houses at (4,3), (1,2), (2,3), creating 3 houses in total:
(=(built_houses loc_43) 1)
(=(built_houses loc_12) 1)
(=(built_houses loc_23) 1)
Note, it may take a minute or two to find a plan, depending on your computer. You should submit your
completed problem and domain files using the names _studentnumber_part1_problem and
_studentnumber_part1_domain respectively.
Part 2: Temporal Planning (35 marks)
In Part 2, you will improve on your initial model by applying temporal information to make temporal plans.
All of the information from part 1 is valid, and some additional temporal information is supplied below. You
CS823 – Reasoning for Intelligent Agents
Computer and Information Sciences
University of Strathclyde
Created June 2023
By Dr Andrew Abel
should use this to create a problem and domain file in pddl. The goal is the same as part 1. You should
produce a plan which is calculated in minutes.
Additional Information:
Distances are the same in both directions:
(0,4) – > (2,4) – 18km
(1,2) - > (0,2) – 7km
(3,2) - > (4,2) – 4km
(4,3) - > (4,2) – 5km
(2,1) - > (2,0) – 5km
(1,2) - > (2,1) – 4km
(1,2) - > (2,3) – 8km
(2,1) - > (3,2) – 3km
(2,3) - > (2,4) – 9km
(2,3) - > (3,3) – 6km
(3,2) - > (3,3) – 7km
(3,3) - > (4,3) – 5km
Due to the condition of the road, all speeds on the island are limited to 20km/h. There is also time
information. It takes time to load the trucks at the depots:
Loading times: brick - 60 mins, wood – 40 mins, glass 30 mins, brick – 60 mins
All unloading takes 20 minutes regardless of material
It takes the architect 50 minutes to design a house, and the builder 70 minutes to construct it.
Note, it may take a minute or two to find a plan, depending on your computer. You should submit your
completed problem and domain files using the names _studentnumber_part2_problem and
_studentnumber_part2_domain respectively.
Part 3: Model Analysis (30 marks)
Using the model you created in part 2, and assuming the goal is to build 1 houses in locations (4,3), (1,2),
(2,3), creating 3 houses in total:
(=(built_houses loc_43) 1)
(=(built_houses loc_12) 1)
(=(built_houses loc_23) 1)
answer the following questions. All questions should be answered in depth, with a discussion of how the
options affect your model, as well as showing what changes you made to the model to investigate the
question.
CS823 – Reasoning for Intelligent Agents
Computer and Information Sciences
University of Strathclyde
Created June 2023
By Dr Andrew Abel
3.1 Vehicle improvements (10 marks)
Management has asked you for your recommendation regarding vehicle improvements. They have a choice
of either improving the existing vehicles (builders, architects, trucks) so that they go 20kmh faster, i.e.
doubling the speed from 20 to 40, or adding an extra truck. With reference to your model, and showing your
working, give your recommendation.
3.2 Staff Training (10 marks)
Management has asked you for your recommendation regarding training. They have two possible training
programmes that may improve performance and would like your advice of which one would be better. They
can either training the loading staff to reduce all loading times by 20 minutes, or they can train their builders
to reduce house building time by half and also use standard designs so that the architect’s design time is
reduced to only 5 minutes per house. With reference to your model, and showing your working, give your
recommendation.
3.3 Infrastructure Improvement (10 marks)
The local government have also proposed improvements. They have proposed to build a new road. The
choices are:
1) Build a single highway from the brick depot at location (0,4) to location (2,3) of length 10km,
2) Build 2 smaller highways one from (2,3) to (3,2), and the other from (1,2) to (3,2), both of length
3km.
They have asked for your advice as to which will improve the speed of house construction. With reference
to your model, and showing your working, give your recommendation.
Submit your answers as a pdf file and also attach any supporting PDDL files you need.
Submission Instructions
You must submit a minimum of 5 files:
1. the domain and problem files for part 1
2. the domain and problem files for part 2
3. a pdf file for part 3 (along with any other problem or domain files you feel are needed)
Use your student id number for the file name, and then label as part 1, 2, or 3 as appropriate.
Additional Notes
Parts 2 and 3 will likely require the use of the Optic Planner on a linux machine that you needed to use
during the semester. Please see the guidance on MyPlace for installing this.