Museum disposal is often surrounded by fear and uncertainty. There are plenty of cautionary tales about past errors, like the sad story of the Royal Cornwall Museum selling a painting by the 19th-century artist John William Waterhouse for £200 in the 1960s. The painting, which was sold to raise money for storage and a lift, is now worth over £5m.

Or the sale of South Asian and Far Eastern metalwork by the Birmingham Museum and Art Gallery in the 1950s. This was highlighted in the National Museum Directors' Conference report Too Much Stuff, and resulted in a significant gap in the museum's collections relating to the growing South Asian community in Birmingham.

Examples such as this, together with the ever-present spectre of councillors selling off collections to reduce deficits or generate income, or the genuine concern that disposals damage the public's trust in museums, have created a sense of unease around disposal.

This is often compounded by misconceptions about the Museums Association's (MA) view on the subject. Some museums are unwilling to even consider undertaking any form of disposal. But well-thought-out disposal can be a key tool for curators and with growing numbers of museums finding storage space full it is becoming increasingly necessary. If museums are unable to dispose and collect, they cannot renew, reinvigorate and re-examine their collections.

It is of course possible to reduce the need for disposal by having in place a well-planned acquisition policy, which many museums now have. But numerous museums have to contend with past collecting practices, which at best could be described as quirky and eccentric - at worst, shambolic.

While we can argue that the richness and uniqueness of museum collections is a result of these practices, it has also left museums with material they do not need and cannot use. This chronic under-use of collections is just one of the problems that could be addressed by disposal or transfer to another museum.

The reasons for disposal are numerous: deteriorating condition, duplication and lack of relevance to the collection are just a few. Although the process of disposing of objects from your collections can be time-consuming, if done well it can result in real benefits for museums and the public. There are a growing number of museums that are engaging in, and successfully managing, the disposal process.

The National Railway Museum (NRM) in York and Newark Museums are among those conducting a review and rationalisation of their collections. Both have consulted others as part of a lengthy process to identify objects for disposal.

The NRM's diesel locomotive 530033 Glorious is a good example. As well as involving senior management, curators and interpretation staff in the decision-making process, the museum canvassed the views of volunteers who had worked on the train during its 11 years at the museum.

At Newark Museums consultation is being achieved through the formation of a panel of interested volunteers who, after receiving training from museum staff, now contribute to the decisions about the retention or disposal of items from the collection.

One of the reasons for the NRM's and Newark Museums' consultation with stakeholders was a recognition that those outside the museums hold important knowledge about items in the collections. Newark's panel included people with a knowledge of arts, archaeology and history as well as someone with a background in engineering who could speak on behalf of that part of the collection.

Helen Ashby, the head of collections at the NRM, oversees many of its disposals and understands the importance of consulting stakeholders. But she says there are times, for curatorial or ethical reasons, when it is unable to follow the wishes of stakeholders.

Newark Museums and the NRM have both successfully transferred objects to other registered museums. This includes the 530033 Glorious locomotive, which found a new home at Steam: the Museum of the Great Western Railway in Swindon.

Some argue that curatorial staff are the only ones qualified to make decisions about disposal, but there are considerable benefits to collaborative working. It fosters a better understanding by the public of curatorial practices and the rationale behind disposals, and can create advocates to speak on the museum's behalf and articulate why decisions were taken. And it can help to shape a collection that reflects the needs and interests of visitors.

While the MA has a strong presumption against disposal, particularly through sale, this does not outweigh the overriding presumption of use for museum collections. If better access and interpretation can be provided for objects through disposal or transfer to other museums this can only be beneficial. Whatever way a museum approaches the complex issue, one thing is clear - it is a problem that will not go away.

Caitlin Griffiths is the adviser: professional issues at the Museums Association