As Chipotle Mexican Grill (CMG 0.17%) tries to bounce back from its damaging food-safety crisis, the company sees online ordering as a huge potential growth driver.

However, customers don't like the most recent version of Chipotle's mobile app whatsoever. Furthermore, the company's mobile order and pickup system doesn't work nearly as well in practice as it does in theory.

The promise of mobile ordering

In the past, one of Chipotle's biggest challenges has been keeping "throughput" high during peak hours. Long lines are a sign of high demand, but when the lines get too long, Chipotle risks losing business from customers in a rush.

Online ordering offers a potential way around this problem. Chipotle can make orders that come from its website and mobile app on a separate service line in the back of its restaurants, allowing it to boost sales while keeping lines manageable at peak hours.

The interior of a Chipotle restaurant

Online ordering could increase the throughput of Chipotle restaurants. Image source: Chipotle Mexican Grill.

In recent months, Chipotle has upgraded its website and mobile apps to encourage more mobile ordering. It has rolled out a new system for estimating pickup times, cutting wait times for mobile orders by about 50%.Some higher-volume stores also have a new digital order display system for the second "make line" designed to increase speed and accuracy.

But people hate the new app

The bad news is, the most recent version of Chipotle's iOS mobile app has been widely panned, receiving a dreadful two-star rating in the App Store. There are two extremely common complaints.

First, the current version of the Chipotle app seems to have a bug, so that when some users search for nearby restaurants, nothing comes up. As a result, they can't place an order.

Second, Chipotle's updated mobile app has removed the option to add a note. Instead, users are allowed to customize their orders by asking for light, medium, or heavy portions of certain components. However, that means customers with allergies no longer have the option to request rice without cilantro, for example. This change may have been implemented to improve kitchen efficiency.

Inconsistent service

Earlier this month, I decided to test out Chipotle's mobile app for the first time. However, I encountered a third seemingly common problem: My order wasn't ready on time.

My order was supposed to be ready at 2 p.m. When I arrived at my local Chipotle restaurant a minute or two after the hour, there was no line -- but my burrito wasn't ready.

The Chipotle Mexican Grill logo

Chipotle's mobile ordering system doesn't always work as it should. Image source: Chipotle Mexican Grill.

An employee quickly found my paper order ticket, but nobody had seen it before, even though it wasn't busy in the restaurant. He then began to make my burrito on the main service line. I offered to tell him what I wanted, but the employee said he had everything on the ticket. However, since he had to look down at the ticket after adding each item, it took twice as long to make the burrito as it normally would have.

The checkout process was equally painful -- especially considering I had already paid. It took the woman working the cash register two or three minutes to find my order in the system to confirm that I had picked it up.

In all, using the mobile app added up to one of the worst experiences I have had at Chipotle. Unless I start running into very long lines at the restaurant, there's no reason I would use the app again.

Chipotle needs a consistently good mobile ordering experience

Chipotle plans to roll out another enhanced version of its mobile app later this year. That should presumably fix the bug related to finding nearby restaurants. The new app may also restore the option to add a note.

However, that won't help much unless Chipotle can also ensure a more consistent experience when customers arrive at the restaurant. Order tickets should never go missing -- and they should be completed on time. There should also be a quick, foolproof way for the restaurant staff to confirm that an order has been picked up.

Chipotle is counting on strong growth in online and mobile ordering to help drive its recovery over the next few years. To achieve that kind of sustained success, it will need to create a much better app and ensure a seamless pickup experience.