Can a Scrum Master serve as a Solutions Lead and Architect all at once? What is really the downside? [duplicate]

Question

Every book/blog or Coach (and more recently, a 3 day workshop I attended) says having the scrum master serve as a solutions lead or architect is a terrible idea. Though I can't get a clear answer as to why this is.

I'm in a mid-sized yet spread-too-thin company with a 3 member team and Agile is currently being forced down our throats.

Is multitasking (not being able to function effectively in any of these three roles) the biggest downside to this? Any anecdotal evidence to share if people have attempted this? Or is there a conflict of interest (Architects and Solutions Leads swim in details, the Scrum Master just wants to make sure things get done)?

I'd like to make a strong case to the higher ups against this but I do not have enough experience (nor would I like to do a proof-by-failure experiment) to sell this to them.

Edit: Note that the other post asked about a Scrum Master being a Functional Manager (Waterfall role). This question actually asks about combining Scrum Master with two developer-centric roles (Architect and Solutions Lead) => Thereby making this question quite different. In my case, we all (entire Agile team) report to a Functional Manager who does our performance reviews, recruits, procures etc. in the traditional Waterfall manner.

Answer 1

I've been Scrum Master, Product Owner and Team Member/Dev Manager all at the same time before and while it can work just fine, the negatives you point out are exactly it - time and conflict of interest.

You need to be able to split time amongst those roles yet not let any of them suffer and set priorities without conflict.

What happens if you're nearing the end of a sprint, you have a development task that you need to finish or else it will block the project, yet another team member has a high impact task that is currently blocked and the Scrum Master needs to deal with it? Which role do you focus on? This might be able to be mitigated by putting your task back on the backlog for someone else to pick up while you focus on the block, but that may not always be practical. This can lead to sprint commitments not being met.

All that said, we live in the real world and sometimes there's no choice but to combine roles. It can work, but everyone has to be realistic about what they're losing by doing that. I found it works best when there's an unwritten agreement within the team that the Scrum Master/Team Member usually works on the smaller/less impacting development tasks as they could have to drop work at any time to deal with Scrum Master duties. It's all about communication.