Sometimes convincing the "powers that be" to spend funds on program evaluation is much worse than pulling teeth. Because the end product seems intangible or not explicitly mission-related, leadership must have a strong, focused, and prospective viewpoint to see the tremendous value in evaluating programs. In my experience, nonprofits and governments often have a hard time documenting what they do. This means nearly all of the feedback about their activities and the effectiveness of their programs is anecdotal at best. Everyone feels the pressure to do the work required to meet the mission and spending time or money to improve processes is just not a priority. The problem is this system will quickly exhaust itself. One way or the other the immensity of your inefficiencies will become unbearable. So, I am going to answer the question here. Yes, you need to conduct evaluation activities and you probably need an external evaluator. Here is the reason why.
The primary benefit of external evaluation is having an unbiased, extrinsically motivated strategy for assessing the success of a program or organization. Nonprofits, especially those mid-sized or larger, tend to develop inefficiencies that they may not immediately recognize while they are busy doing the work. Even more so, many of the staff learn to work around these inefficiencies; unknowingly perpetuating their effect on operations.
Many nonprofits undervalue the amount of efficiency and cost savings derived from sound evaluation strategies. They are busy meeting the mission and tend to do so very well. However, meeting the mission also means conducting activities in a way that is positively effectual for staff, their client base, and their stakeholders. External evaluation allows an outside entity to assess an organization’s level of productivity, cost, and impact—in the background. External evaluators can observe, collect information, and analyze while the staff is busy doing the work their mission requires of them. Evaluators can then tell the organizational staff about the characteristics of those activities. Doing so incrementally and reporting with factual and a non-anecdotal accounting of the impact of those activities can drastically change the “reality” of programming at an agency.
Programs funded by federal agencies are often expected to show impact in a uniform and data-driven manner. With the increasing popularity of evidence-based strategies, more and more funding agencies are looking for data-driven results. Formative evaluation is done before you implement a program and it forces you to see the potential problem areas in your plan. Process evaluation activities help uncover warning signs or problems as they occur early in the program. Identifying these factors provides opportunities for correction early in the development of the problem so you can fix them before they become insurmountable. This is both efficient and cost-effective. Outcome evaluation activities determine if the program was able to produce the results it originally set out to produce. I bet you never thought that it is possible to set out to fix the problem using a particular strategy and then not even recognize when you are not following your own plan. Outcome evaluation will likely tell that undeniable truth (maybe too late), but formative and process evaluations will keep you from getting that far into the abyss of failure. Evaluation strategies work together to help determine impact (that can then be measured by an impact evaluation). That, my friend, is why you set out to do the program in the first place--to do things that fix the problem. Impact means you have fixed something that you set out to fix. Fixing a problem you didn't have is possible without evaluation. Your grantmaker won't want to hear much about that impact though (insert side eye).
How will you ever really know you did a good job without creating a system for measuring your success? Imagine your kid getting an 'A' in a class but then you find that the teacher never graded any papers. How much would you trust your kid's teacher to guesstimate or memorize your child's grades all year and to then assign a grade based on her experience with your child--not actual grades? Why would you think you can run an important program that way? So it is not extra work; it comes with the territory. If you are skipping evaluation you are doing yourself and those you serve a disservice. Having these practices in place greatly improve an organization’s ability to demonstrate success and return on investment to your clients, grantmakers, stakeholders, and the community. Don't underestimate the benefit of an evaluation plan even if you feel you need to do it internally. Anytime you can have it done by an outside, unbiased entity your chances of seeing things for what they really are greatly increased. At any rate, just create an evaluation plan and implement it.