I created this diagram recently but, it's one of those things that has been brewing for quite some time. Several years ago I conducted a series of interviews with designers who were developing/designing new design methods. These three requirements for a design to be considered "good" was one of my takeaways from those interviews. I sometimes call it "The 3 E's" of design. I like it because it forces the designer to balance the 3 E's in their design. One E cannot be accentuated at the cost of another.
Over the years the ideas here have remained solid with one grey area -- defining "enjoyable." Unlike "efficient" and "effective," "enjoyable" is difficulty to quantify. It is based largely on the users preferences and so requires a deeper understanding of the user and the context of use. For example if you are designing an app for a construction worker to use on a job site then "enjoyable" means something very different than it does for an app for vacationers lounging on their balcony. The low bar for "enjoyable" could be that it is not tedious or unpleasant to use. I'm not a big fan of aiming at the low bar.
Yesterday I read an article titled "Most designs are boring." It's a short, pleasant and thought provoking article about the difference between a design that is good and one that is somehow more than that -- the word "delight" is used. It is likely possible that a designer can put a number on "effective" and "efficient," but "enjoyable" is not so quantifiable and as such allows or even demands the designer to do unusual, interesting and compelling things.
There is a trend in IX/UX design to systemize a design. And I agree with some of the ideas there. Unfortunately, systemizing a design usually means setting your "enjoyable" bar at the lowest possible point -- eg. "Well it's not tedious or unpleasant to use so it's good." I'm regularly involved in critiquing the work of young IX/UX designers and this is where my job becomes most interesting(?). A young designer might come to me with a design that is clean, smooth, easy to use and tics each of the 3 E boxes. But, it's just boring! It's a difficult task to help them understand that their design can be so much more while still balancing the 3 E's. But that is the difference between a "good" designer and one that infuses their designs with a little delight.