Tesla has learned from the hubris that CEO Elon Musk blamed for delays and issues with the Model X, and is applying those lessons to the Tesla Model 3. The all-electric Model X SUV finally went on sale at the end of 2015 after a long 18-month delay, and even once deliveries started it took a while to ramp up production rates — last year Tesla built a whole 507 units of the Model X, while in the first quarter of 2016 built 2,659 of them.
Currently maintaining their goal of starting production at the end of 2017, Tesla has set an internal goal of being ready to start Model 3 production by July 2017 — a goal which Musk described very literally as "impossible" on the Tesla Q1 2016 earnings call:
In order to achieve volume production of a new car with several thousand unique items, you actually have to set a target date — internally and with suppliers — that is quite aggressive. That is a date that has to be taken seriously. ... The date we are setting with suppliers to get to volume production capability with the Model 3 is July 1st next year.
Now will we actually be able to achieve volume production on July 1st next year? Of course not. The reason is that even if 99% of the internally-produced and supplier items are available on July 1st, we still cannot produce the car, because you cannot produce a car that is missing 1% of its components. Nonetheless, we need to both internally and with suppliers take that date seriously and there need to be some penalties for anyone internally or externally who does not meet that timeframe.
This has to be the case, because there's no way that you have several thousand components all of whom make it on a particular date. ... You have to take the July 1st date seriously in order for some date a number of months later to actually be the real date. That's actually how it has to work. In order for us to be competent of achieving volume production of Model 3 by late 2017 we actually have to set a date of mid-2017 and really hold people's feet to the fire, internally and externally, to achieve an actual volume production date of late 2016.
The Model 3 will have 6,000 unique components, constituting roughly 3/4 of the vehicle's parts. Tesla's early deadline setting for external suppliers is also to set themselves up to be able to produce parts with another supplier, or even internally, if they won't be close to ready by then. Additionally, Musk said that they are working to make the car far simpler than the too-complicated and issue-prone Model X, saying that they're working to ensure they're not installing any unnecessary features — like falcon wing doors.
Tesla is actually aiming to produce between 100,000 and 200,000 Model 3 cars in the latter half of 2017 — we'll see if they're able to meet that target. They've received roughly 400,000 reservations for the car, and Tesla has seriously ramped up its production plans to get to 500,000 total cars a year by 2018, split between the Model 3, Model S, and Model X. With that number in mind, Musk said that those that reserve a Model 3 now should be able to have their car delivered by the end of 2018.