A departmental proposal is generally used to obtain resources for a new or expanded program, a new service or a different way of doing current business that will require approval for spending the department's budget allocation. It needs to be brief enough to respect the decision maker's time, but comprehensive enough to gain approval. A proposal may be a response to a Request for Proposal (RFP), or it may be unsolicited.
Do your research. Read the RFP or the departmental proposal guide thoroughly. Know what they are asking for (format, length, number of sections). Follow the instructions precisely; do not improvise.
Know who you are presenting the proposal to: the CEO, the management board or a departmental manager. You will need to pitch the proposal to their point of view. The CEO will need a more strategic view, whereas the manager will require more procedural detail. The management board will consist of both, so both goals should be well documented.
Read the departmental strategic plan, or equivalent. You will need to show how your proposal fulfills a strategic objective, or key result. Read any other pertinent departmental documents, particularly those that reference the area you are working in.
Start with a history of the problem you will solve, or service you will render. Describe the need or provide a needs analysis. Show your understanding of departmental structure and where this proposal will fit in.
Identify the benefits of your proposal -- quantitatively if possible. Highlight the strengths and opportunities quantitatively, and show solutions to weaknesses and threats. Describe options and possible alternatives in terms of relative costs and benefits. Do a risk analysis; include legal considerations and identify solutions to identified risks. State your preferred option, and show why.
Identify the human and material resources that will be required for the recommended option, in terms of both number and cost. Make sure all your claims are accurate and you have the resources to supply the results that you are promising.
Clearly state the time frame of the work. Include a basic work breakdown structure or a Gantt chart, which are both project management tools. If you are unfamiliar with them, then find a colleague who is. Be sure to include the names of any colleagues who provide significant help, either verbally or in the proposal.
Before submitting the proposal, set it aside for 24 hours. Read it thoroughly, and identify any weaknesses; tighten up grammar. Ask someone you trust to proofread, and rewrite if necessary.
Create an executive summary. In one page or less, state the important parts of the proposal. Put this as the first page. The second page should be an accurate index or table of contents.
If you are to present in person, practice your presentation in front of a mirror, or present to a colleague as a dry run.
Never promise what you cannot deliver or make claims that are unfounded or untrue.