Group retirement plans provide one of the best tax-sheltering opportunities available and can be a significant benefit to employees. With the long term viability of government sponsored pension plans in question, group retirement plans together with individual RRSP plans play a major role for most Canadians in saving for their retirement. From the viewpoint of the plan sponsor, group retirement plans can play a very significant role in attracting new employees and increasing employee retention. 
There are many options available when putting together a group retirement plan. Factors that should be taken into consideration when determining which options are appropriate include:

Contribution levels: Should the plan be contributory or only funded by the employer? What percentage should the employer contribute? Should there be a matching formula? 
Contribution Flexibility: Should contributions be uniform? Linked to profitability? Discretionary? Linked to years of service?

Vesting and Eligibility: Should the plan vest immediately (maximum vesting period is 2 years)? Who should be eligible for the retirement plan and after how long?

Administration: Is plan administration practical given the size of the workforce and the objectives of the plan?

Costs: What are the costs associated with each option? Are the costs reasonable given the objectives of the plan? 
Only after a very thorough review of all the retirement options and the implications of each can an appropriate group retirement plan be developed.