Making cars and writing code: Production Line's refreshing dev approach

Gamasutra chats with veteran indie Cliff Harris (aka Cliffski) about the work that went into turning car manufacturing into an engrossing game in his Early Access puzzler Production Line.

Production Line, which has been in Steam Early Access since mid-2017, is a business sim built around seeing how well the player can create an assembly line for cars.

Having a shrewd eye for cost, a willingness to experiment with future tech, and a careful hand at planning will all be necessary if you’re to be able to tangle with the big multinational manufacturers. With so many possibilities for factory creation, though, the title offers many, many different ways to tackle the competition.

The game  is a complicated title with a deeply-researched set of mechanics tied to real-world car manufacturing, yet it all lies in the hands of a single developer: Cliff Harris of UK-based Positech Games (Democracy, Gratuitous Space Battles series).

Gamasutra reached out to Harris to talk about the work that went into turning car manufacturing into a game, how he gave players multiple means to build their dream factory, the challenges and benefits he’s found in working on something so complex on his own, and what it is that draws him to this intricate genre. In his own words...

On the draws of creating games around complex tasks

I am unusual in that I'm an indie dev who really enjoys the business side. I read a lot of books about business strategy and decision making, and find it really fascinating. Very few people actually work for themselves and start their own business, but it's a popular fantasy, and I definitely think it can be entertaining, as TV shows like Shark Tank and Dragons Den and The Apprentice.

I also think there is a very pleasing Zen-like state of flow you can achieve by really being 100 percent-involved with a complicated task. That level of depth can generate a feeling of mastery and control that really puts you into the moment and immerses you in the task in a way that a simple, casual mobile game can never do.

Everyone wants to feel a state of skill and control, and complex games can let you experiment with that without having to dedicate your whole life to it or take any risks.

Similarities between making cars and writing code

As a programmer, I spend a lot of my time doing code optimization, tracking down and fixing bottlenecks, looking for ways to load-balance stuff, and I know I always get a big rush of endorphins from working out ways to make my code go 1 or 2 or 10 percent faster. I always figure that I'm not especially unusual, and that if I get pleasure from that sort of thing then there will be a bunch of players who enjoy the same mechanic.

I kind of specialize in making games where the objective is just to get certain numbers to go up or down, and when I read a book about Henry Ford and the making of the Model T car, I realized it was a perfect 'real-world' version of the much more confusing and specialized world of code optimization. Plus, people understand cars, and the idea of car factories, so it seemed like a potential game idea that had weirdly never really been done.

On research and how to turn car manufacturing into a game

I went to the Henry Ford museum in Detroit, and also took a tour of a car factory in Detroit at the same time, which was very interesting. I think I also now own every book, however obscure, on car factory design and processes.

The thing is, it’s difficult to translate things directly into a game, because the number one priority of any game is to be entertaining. It’s also the case that you have a hard time if people have in their head that something works like A, and the reality is B. So, for example, in a lot of places in factories, cars move on powered skates rather than conveyor belts, but people really like and assume the existence of conveyor belts, so here we are :D.

Finding the challenge in creating an assembly line

It really depends on the mix of what cars you wish to make AND the amount of funds and research you have. Production Line has a big tech tree, so for 95% of the game you have not researched everything, meaning at different points in the game, the time taken at each station will vary.

For example, fitting brakes is initially quick, then you get anti-lock brakes, then cruise control, and other techs that require additional resources and time at that station, which then might shift fit brakes from being a simple slot on the line into a serious bottleneck. The *right* way to layout your factory is changing *all the time*, especially when new body styles are researched.

The thing I wanted to capture is the pleasure of 'enjoying the journey'. You never finish optimising code - the bottlenecks move but can never be solved - and I am attracted to the idea of games with no 'solution' or upper limit to what you are attempting.

Democracy 3 is the same, as there is no 'right' way to play it, and no solution that is perfect. I enjoy sandbox games, and games where you build something big and complex, and also I really love tech trees. Car technology has gone bananas in the last decade, so it seemed like a perfect area to dive into all the tech and options.

On inspirations from other business sims

I love the sense of 'flow' you get from when a system is working as intended, and I also like the general principle of investing now for future gains. That’s actually a decent principle to learn for your life, and games can teach it really well. For me, a biz sim has to very carefully manage the difficulty, and allow a lot of freedom, and ideally no absolute perfect solution. No perfect solution exists in the real world of business, everyone is chasing different approaches and strategies, and I think it’s important to simulate that in a biz game.

I was the publisher of Big Pharma, which has a similar style, and I really enjoyed that game but wanted to take it in a different direction. I've also played a lot of isometric biz sims over the years like Rollercoaster Tycoon.

I also really enjoyed Factorio, although I only really discovered it after I had started on Production Line and people kept mentioning it to me and assuming I had played it. Factorio is great, but for me, it lacked a constraining factor in terms of costs or business rivals.

The biggest way Factorio influences Production Line is its code optimisation. There probably aren’t *that* many coders who truly appreciate the extent to which those devs have coded a really optimized engine, but I'm definitely one of them :D.

What didn’t make it into Production Line and why

There are some really trivial things that we cannot do visually without vastly bloating the game’s art requirements and min spec. One of those is to have cars sink down into those cleaning bath things that some factories use before painting, because graphically that would be *a pain*.

Another is that our cars just make 90 degree snap-turns. Only one player has ever complained about it, and I think it’s something you can accept in a game. I would like to have some lighting effects that really made the welding robots 'pop' in terms of illuminating the scene around them, but its a whole world of extra rendering and requires darkening the rest of the factory to notice it, and frankly nobody cares about it but me :D.

How to capture the complexities of car assembly for a lone developer

For a new indie, Production Line would be a stupidly ambitious, complex, and unwieldy task, especially for a solo coder, and especially given that I coded my own engine too. The only reason it’s vaguely possible is that I can combine being a workaholic with also 20 years of indie dev experience and 37 years of coding experience.  Anybody who wants to attempt a game like this, in Unity, as their first game is nuts. Don't do it – it’s seriously, ridiculously hard.

For me, the thing I really screw up on is art direction for stuff like the UI. The UI is in a constant state of improvement, hopefully always getting better, but as a developer, I consider the UI styling to be a weakness for me.

The benefits of working alone

We have no long design meetings or arguments because it’s just me. If I have an idea, or a player suggests one, I can just code it. I don’t need anyone's agreement or permission.

The disadvantages of being a lone developer

Only in terms of graphical fidelity, and maybe UI polish. It does amaze me how simple some biz sim games can be that are made by huge teams. I think often the extra money and time gets put into really peripheral stuff that does not make for a significantly better game.

For example, Production Line is an isometric game, but I really don't think it would be twice as good in 3D (or even as good...). It really wouldn't be worth it to spend a ton of time and money on a voice-over, or on some FMV at the game’s start. Games like these are about carefully designed and balanced systems. That’s often done by a relatively small team anyway.

On facing the complexities of development alone

Hugely unhealthy levels of overwork have been my go-to strategy for this :D. I don’t have a ton of hobbies, I have no kids, and I do this full time, so it’s just about achievable. Even with all that being the case, players forget that some games are made by 30 developers and some are made by one.

I do suspect a lot of people think I'm just the 'frontman' for Positech Games and we have a 'team' working on the game, but it is genuinely just me. The guy in the weekly YouTube videos is me, and he is the guy who also renders, edits, and uploads them, and then goes back to coding while they upload.

It’s funny, because suddenly I'm being represented in some places as some poor overworked indie who is close to death. I sat here typing away in my home office with a 10 month old kitten sat just in front of the keyboard, a freshly-made cup of tea on my desk, and zero noise or distractions from a normal office or place of work. It’s great. I do work long hours by any conventional measure, but my job is also my hobby and something I absolutely love. I could work less hours, but choose not to.

In terms of helping to relax, I do make time pretty much every day at 6PM to jump onto Discord and voice chat with some buddies as we play Battlefield 1. That’s my stress release. And stroking the kittens.

How Early Access has affected Production Line’s development

I love it. I was scared of it, because you hear horror stories of angry players and negativity, but somehow I have gotten a really helpful and friendly community. Some people can be a bit *too* insistent that you are making the wrong decisions, but it never turns to anything abusive or angry.

I stay in touch with players in a lot of different places very regularly, and I think the key to having a decent experience with Early Access as a developer is just to ensure that you are always keeping the community up to date and informed about what you are working on, what changes are coming and the thinking behind them. I'd definitely do Early Access again in the future.

Oh, so many cool ideas have come from comments on YouTube or my forums or the steam forums. A lot of them are fairly minor about balancing certain parts of the game, but the redesign of the showroom UI was entirely player-prompted, and every few weeks I re-set a poll to ask players what their priority is regarding features.

I would have spent a LOT more time on extra graphics and animation and sound effects and less time on new features and optimisation for bigger factories if I had not listened to my Early Access players. They are massively helpful.

Latest Jobs

Manticore Games

San Mateo, California
Senior Software Engineer - Mobile

Sony PlayStation

San Diego, California
Sr. Online Programmer

The Walt Disney Company

Glendale, California
Associate Marketing Manager - Walt Disney Games

Insomniac Games

Burbank, California
Accessibility Design Researcher
More Jobs   


Explore the
Subscribe to
Follow us

Game Developer Job Board

Game Developer Newsletter


Explore the

Game Developer Job Board

Browse open positions across the game industry or recruit new talent for your studio

Subscribe to

Game Developer Newsletter

Get daily Game Developer top stories every morning straight into your inbox

Follow us


Follow us @gamedevdotcom to stay up-to-date with the latest news & insider information about events & more