Do you think when selecting a project manager the individual should not be from a particular discipline?

Thanks for the question Erika, a great one.
I believe that most people (if not all) are biased towards their knowledge and experiences, and rely on their background (as this is their core strength after all) to perform tasks, hence, I have to say, I have seen project managers who limit and constrain their project to the areas they understand, and try to implement what they know in that project, which may drift the project from its intended purpose.
We can argue that a project manager should be a person who is resourceful, able to manage teams, deliver according to project timeline, scope and budget, and be unbiased, and we may argue that knowledge about certain topic would not be needed to manage the project, and having a technical team will lead you to properly perform.
But, we need to realise that we cannot neglect bias towards a topic from previous experiences.
A project manager who may have faced an issue in a previous project (let's say in project finances), will more likely be focused on project finances in the next project, even though he may be working in a totally different culture (like aerospace, who generally go over budget in almost all projects, and getting approvals is considered a normal process).
Therefore, there are few things every project manager should do to mitigate this:
1- Remind yourself about the purpose of the project, think in the overall impact of the project, every once in a while, read the project charter, try to think of the project from the perspectives of the different stakeholders, not only finance, operation, marketing, IT, etc...
2- Select a team whose technical skills is sufficient to debate in case you drifted from the project purpose, train them in project management, it’s inevitable they will manage projects later, brainstorm with them, get feedback
3- Communicate, and listen to others, get their feedback about your thoughts and ideas, get their input, correct accordingly Sorry for the long answer, but couldn't answer this very valuable question briefly.

Thanks to Erika for the valuable question and also be transferred to Tamer for his great answer.
The selection of a project manager for any project , must be according to basic criterias related to project management profession for example interpersonal skills.leadership skill,comprehensive professional experience and the ability to lead and manage team work with muliti-culture and from different nationalities .
When the above criterias are satisfied , then you will have the project manager who is capable to acquire the good team with suitable technical skills to execute the project under the constrains of time,budget and resources.
So the discipline from which the project manager is selected ,has not the exclusive effect on the project success,

I beleive from my expereinces that the best project manager (PM) is the guy who can combine the following:

1- Technical expereince in the same field/descipline

2- Great project management expereince

But in my opinion if PM has no#1 but he has n't no.#2 then the project will be lost.

I dont think so.
Because a Project Manager should able to handle all descipline including finance.

I think for majority of the cases, it's unwise to NOT select a PM because he/she is from a particular discipline. Project management is all about applying Art and Science. Art is what a PM is, interpersonal, conflct management, background, experiences. Science is all about knowledge about project management and especially standards, ex: knowing what is a CPM, Scheduling, Risks etc etc. So, one could think that while NOT selecting, his/her Art is being questioned and may not want those Art to be applied due to specific reasons which I guess should be very rare.

Knowledge of the domain will help 'talk the talk' with the stakeholders however smart PM's just get what Art has to be applied the moment they review the charter and initial discussion with stakeholders. The beauty of PM skill and I believe with finance too is that irrespective of the function we should be able to relate to all the industries. I have seen folks who has done Civil, Railway, IT, Rocket launching project and programs with ease and smartly. So, it's all about knowing PROJECT MANAGEMENT rather than anything else. Typically there is a preference for folks who knows the domain well than others who doesn't know the domain but as long as PM's are smart enough- which should be figured out during the interview :-), we shouldn't stop anyone because of a specific backgroud or proficiency.

Thanks,

Abdul Rahiman

PMP,RMP,SP,ITILv3,CSM.

Short answer :NO - Yes Project Development can be a sub specialization lets take my own example I am holding over3 decades of experience as a Hospitality field professional.
What would I know about Projects Development .
But over my thirty years in my specialized field I have opened many properties and have became practically savvy to the vulnerabilities.
What I had to learn was the discipline of Project Management.
So yet again the moral of the story is no matter how savvy or experienced you are in your particular field of expertise it certainly is of great value but is no substitute for the disciple of Project Management itself.
It is a different and versatile  science which carries along with it various science of any particular project it imbibes into.

Hi Erika,

Well, Yes, Psychology plays a good part with the job you were used to doing. I've noticed this all my life (I am young though)

If you are looking for a PM to deal with EPC, then similar experience is mandatory and you can't have someone with Bid Management instead. As you mentioned above, it will cause a well-imbalance in the project.

Moreover, I don't go with the statement that a good PM can handle projects from all verticals, if so, I would want to see some PM with a Real Estate Background all his/her life, dealing with NASA's Mars Odessey. It doesn't make sense.

First you need to prove that you can create a model, that works by itself, so that in the absence of the project manager itslef, the model will do job for him. This is enormously difficult because sometimes it would last more than doing the project; but this is where you start breaking down the structure of work so it can granular enough to be modeled. So if anyone can do this they can do almost any area, as long as the team can fill in the holes, due to the degree of specialization needed for specific tasks.

I would be a little controversial on it. Before being PM, one should be a good professional in the field. You cannot be a good PM for an IT project without knowing anything about programming, You can be a PM, but you'll lose a lot of time trying to understand the real issues, not to mention that you'll have to fully rely on the programmers to know whether a solution is appropriate or not. And, these guys are being in a litle bit of conflict of interests, isn't it? On one hand, they should deliver, on the other hand, subjectively, they will provide the solution which is more comfortable for themselves. Same in any other project, or field. And this leads to another problem: Selection is made, in first instance, by HR specialized individuals, which are mainly specialized in psichology or related fields, and rarely capable of properly asessing the purely professional skills, which may lead to situations when applications of the most skilled PMs are not selected, while thyose of less skilled, but more psichologically "on standard" are.

He can be from any discipline but well versed in the Project Management.

Well, the IDEAL project team is a 'heterogeneous' mixture - comprising of members from different backgrounds - both social, professional and technical.
Still, every project team MUST DELIVER 'homogeneous' results - meeting the defined business objectives while remaining aligned with the goals, aims, ethics and culture of its sponoring organization as well as its customer.
A mature project manager thus is one who is capable of leaving behind his/her own professional and social background and is capable of leveraging the diverse experiences of his/her team - and synchorinize them all towards chieving the define objectives.